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</style><table class="infobox vevent"><tbody><tr><th colspan="2" class="infobox-above" style="background-color: #e0e0e0;">Multics</th></tr><tr><td colspan="2" class="infobox-image"><span typeof="mw:File"></span></td></tr><tr><td colspan="2" class="infobox-image"><span typeof="mw:File"></span><div class="infobox-caption">Login screen for the BAN.AI public Multics server</div></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Programmer" title="Programmer">Developer</a></th><td class="infobox-data"><a href="Massachusetts_Institute_of_Technology" title="Massachusetts Institute of Technology">MIT</a>, <a href="General_Electric" title="General Electric">GE</a>, <a href="Honeywell_International%2C_Inc." class="mw-redirect" title="Honeywell International, Inc.">Honeywell</a>, <a href="Bell_Labs" title="Bell Labs">Bell Labs</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Programming_language" title="Programming language">Written in</a></th><td class="infobox-data"><a href="PL/I" title="PL/I">PL/I</a>, <a href="Assembly_language" title="Assembly language">Assembly language</a><sup id="cite_ref-Mpl1_1-0" class="reference"><a href="#cite_note-Mpl1-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Working state</th><td class="infobox-data">Mature, current, historic, emulator available</td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Source model</th><td class="infobox-data"><a href="Open_source" title="Open source">Open source</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Initial release</th><td class="infobox-data">1969<span style="display:none"> (<span class="bday dtstart published updated">1969</span>)</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Software_release_life_cycle" title="Software release life cycle">Latest release</a></th><td class="infobox-data">12.8 / August 10, 2023<span style="display:none"> (<span class="bday dtstart published updated">2023-08-10</span>)</span></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Repository_(version_control)" title="Repository (version control)">Repository</a></th><td class="infobox-data"><style data-mw-deduplicate="TemplateStyles:r1126788409">

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</style><div class="plainlist"><ul><li><span class="url"><a rel="nofollow" class="external text" href="http://web.mit.edu/multics-history/source/Multics_Internet_Server/Multics_sources.html">web<wbr>.mit<wbr>.edu<wbr>/multics-history<wbr>/source<wbr>/Multics<wbr>_Internet<wbr>_Server<wbr>/Multics<wbr>_sources<wbr>.html</a></span> </li></ul>

</div></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Available in</th><td class="infobox-data"><a href="English_language" title="English language">English</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Supported platforms</th><td class="infobox-data"><a href="GE-645" class="mw-redirect" title="GE-645">GE-645</a>, <a href="Honeywell_6000_series" title="Honeywell 6000 series">Honeywell 6000 series</a> machines (<a href="Honeywell_6180" class="mw-redirect" title="Honeywell 6180">Honeywell 6180</a>, Series-60/Level-68, DPS-8/M mainframes)</td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Kernel_(operating_system)" title="Kernel (operating system)">Kernel</a> type</th><td class="infobox-data"><a href="Monolithic_kernel" title="Monolithic kernel">Monolithic kernel</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Influenced</th><td class="infobox-data"><a href="Unix" title="Unix">Unix</a>, <a href="GEORGE_(operating_system)" title="GEORGE (operating system)">GEORGE 3</a>, <a href="ICL_VME" title="ICL VME">ICL VME</a>, <a href="PRIMOS" title="PRIMOS">PRIMOS</a>, <a href="Domain/OS" title="Domain/OS">Domain/OS</a>, <a href="Stratus_VOS" title="Stratus VOS">Stratus VOS</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="User_interface" title="User interface">Default<br>user interface</a></th><td class="infobox-data"><a href="Command-line_interface" title="Command-line interface">Command-line interface</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;"><a href="Software_license" title="Software license">License</a></th><td class="infobox-data">Originally <a href="Proprietary_software" title="Proprietary software">proprietary</a>,<br>Free software Multics License since 2007<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-myths_3-0" class="reference"><a href="#cite_note-myths-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Preceded by</th><td class="infobox-data"><a href="Compatible_Time-Sharing_System" title="Compatible Time-Sharing System">Compatible Time-Sharing System</a></td></tr><tr><th scope="row" class="infobox-label" style="white-space: nowrap;">Official website</th><td class="infobox-data"><span class="url"><a rel="nofollow" class="external text" href="http://multics-wiki.swenson.org">multics-wiki<wbr>.swenson<wbr>.org</a></span></td></tr></tbody></table>

<p><b>Multics</b> ("<b>MULTiplexed Information and Computing Service</b>") is an influential early <a href="Time-sharing" title="Time-sharing">time-sharing</a> <a href="Operating_system" title="Operating system">operating system</a> based on the concept of a <a href="Single-level_store" title="Single-level store">single-level memory</a>.<sup id="cite_ref-Ritchie84_4-0" class="reference"><a href="#cite_note-Ritchie84-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> It has been written that Multics "has influenced all modern operating systems since, from microcomputers to mainframes."<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup>

</p><p>Initial planning and development for Multics started in 1964, in <a href="Cambridge%2C_Massachusetts" title="Cambridge, Massachusetts">Cambridge, Massachusetts</a>. Originally it was a cooperative project led by <a href="Massachusetts_Institute_of_Technology" title="Massachusetts Institute of Technology">MIT</a> (<a href="Project_MAC" class="mw-redirect" title="Project MAC">Project MAC</a> with <a href="Fernando_Corbat%C3%B3" class="mw-redirect" title="Fernando Corbató">Fernando Corbató</a>) along with <a href="General_Electric" title="General Electric">General Electric</a> and <a href="Bell_Labs" title="Bell Labs">Bell Labs</a>. It was developed on the <a href="GE_645" title="GE 645">GE 645</a> computer, which was specially designed for it; the first one was delivered to MIT in January 1967. GE offered their earlier 635 systems with the <a href="Dartmouth_Time-Sharing_System" title="Dartmouth Time-Sharing System">Dartmouth Time-Sharing System</a> which they called "Mark I" and intended to offer the 645 with Multics as a larger successor. Bell withdrew from the project in 1969 as it became clear it would not deliver a working system in the short term. Shortly thereafter, GE decided to exit the computer industry entirely and sold the division to <a href="Honeywell" title="Honeywell">Honeywell</a> in 1970. Honeywell offered Multics commercially, but with limited success.

</p><p>Multics has numerous features intended to ensure high availability so that it would support a <a href="Computing_utility" class="mw-redirect" title="Computing utility">computing utility</a> similar to the <a href="Telephone" title="Telephone">telephone</a> and <a href="Electricity" title="Electricity">electricity</a> <a href="Public_utility" title="Public utility">utilities</a>. Modular hardware structure and software architecture are used to achieve this. The system can grow in size by simply adding more of the appropriate resource, be it computing power, main memory, or disk storage. Separate <a href="Access_control_list" class="mw-redirect" title="Access control list">access control lists</a> on every file provide flexible information sharing, but complete privacy when needed. Multics has a number of standard mechanisms to allow engineers to analyze the performance of the system, as well as a number of adaptive performance optimization mechanisms.

</p><p>Due to its many novel and valuable ideas, Multics has had a significant influence on <a href="Computer_science" title="Computer science">computer science</a> despite its faults.<sup id="cite_ref-Myths_about_Multics_7-0" class="reference"><a href="#cite_note-Myths_about_Multics-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> Its most lasting effect on the computer industry was to inspire the creation of <a href="Unix" title="Unix">Unix</a>, which carried forward many Multics features, but was able to run on less-expensive hardware. Unix was developed at Bell to allow their Multics team to continue their research using smaller machines, first a <a href="PDP-7" title="PDP-7">PDP-7</a> and ultimately the <a href="PDP-11" title="PDP-11">PDP-11</a>.

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<div class="mw-heading mw-heading2"><h2 id="Novel_ideas">Novel ideas</h2></div>

<p>Multics implements a <a href="Single-level_store" title="Single-level store">single-level store</a> for data access, discarding the clear distinction between <a href="Computer_file" title="Computer file">files</a> (called <i>segments</i> in Multics) and <i><a href="Computer_process" class="mw-redirect" title="Computer process">process</a> <a href="Computer_memory" title="Computer memory">memory</a></i>. The memory of a process consists solely of segments that were mapped into its <a href="Address_space" title="Address space">address space</a>. To read or write to them, the process simply uses normal <a href="Central_processing_unit" title="Central processing unit">central processing unit</a> (CPU) instructions, and the operating system takes care of making sure that all the modifications were saved to <a href="Disk_storage" title="Disk storage">disk</a>. In <a href="POSIX" title="POSIX">POSIX</a> terminology, it is as if every file were <code><a href="Mmap" title="Mmap">mmap</a>()</code>ed; however, in Multics there is no concept of <i>process memory</i>, separate from the memory used to hold mapped-in files, as <a href="Unix" title="Unix">Unix</a> has. <i>All</i> memory in the system is part of <i>some</i> segment, which appears in the <a href="File_system" title="File system">file system</a>; this includes the temporary scratch memory of the process, its kernel stack, etc.

</p><p>Segments are limited to 256 <a href="Kiloword" class="mw-redirect" title="Kiloword">kilowords</a>, just over 1 <a href="Megabyte" title="Megabyte">MB</a>, because Multics hardware had 18-bit word addresses for the content of a segment. Larger files are "multisegment files" and are handled differently. The 256 kiloword limit was rarely encountered in practice, because at the time, one megabyte of memory was prohibitively expensive.

</p><p>Another major new idea of Multics was <a href="Shared_library" title="Shared library">dynamic linking</a>, in which a running process can make external routines available by adding the segments containing them to its address space. This allows applications to always use the latest version of any external routine, since those routines are kept in other segments, which are dynamically linked only when a process first attempts to begin execution in them. Since different processes can use different <a href="PATH_(variable)" title="PATH (variable)">search rules</a>, different users can end up using different versions of external routines. Equally importantly, with the appropriate settings in the Multics security facilities, the code in the other segment can gain access to data structures maintained in a different process. Dynamic linking in Multics does not require special <a href="Dynamic-link_library" title="Dynamic-link library">dynamic-link libraries (DLLs)</a>; a program can dynamically link to any executable segment to which it has access rights.

</p><p>Thus, to interact with an application running in part as a <a href="Daemon_(computing)" title="Daemon (computing)">daemon</a> (in another process), a user's process simply performs a normal <a href="Procedure_call" class="mw-redirect" title="Procedure call">procedure-call</a> instruction to a code segment to which it had dynamically linked (a code segment that implemented some operation associated with the daemon). The code in that segment can then modify data maintained and used in the daemon. When the action necessary to commence the request is completed, a simple procedure return instruction returns control of the user's process to the user's code.

</p><p>Multics also supports extremely aggressive <a href="Hot-swapping" class="mw-redirect" title="Hot-swapping">on-line reconfiguration</a>: <a href="Central_processing_unit" title="Central processing unit">central processing units</a>, memory banks, disk drives, etc. can be added and removed while the system continues operating. At the MIT system, where most early software development was done, it was common practice to split the <a href="Multiprocessor" class="mw-redirect" title="Multiprocessor">multiprocessor</a> system into two separate systems during off-hours by incrementally removing enough components to form a second working system, leaving the rest still running for the original logged-in users. System software development testing could be done on the second system, then the components of the second system were added back to the main user system, without ever having shut it down. Multics is one of the earliest multiprocessor systems.

</p><p>Multics is the first major operating system to be designed as a <a href="Computer_security" title="Computer security">secure system</a> from the outset.<sup id="cite_ref-JHSProt_8-0" class="reference"><a href="#cite_note-JHSProt-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> Despite this, early versions of Multics were compromised repeatedly.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup> This led to further work that made the system more secure, and prefigured modern <a href="Security_engineering" title="Security engineering">security engineering</a> techniques. Break-ins became very rare once the second-generation hardware base was adopted; it has hardware support for <a href="Ring_(computer_security)" class="mw-redirect" title="Ring (computer security)">ring-oriented security</a>, a multilevel refinement of the concept of <a href="Kernel_mode" class="mw-redirect" title="Kernel mode">master mode</a>. A US Air Force tiger team project tested Multics security in 1973 under the codeword ZARF. On 28 May 1997, the American National Security Agency declassified this use of the codeword ZARF.

</p><p>Multics is the first operating system to provide a <a href="Hierarchical_file_system" title="Hierarchical file system">hierarchical file system</a>,<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> and file names can be of almost arbitrary length and syntax. A given file or directory can have multiple names (typically a long and short form), and symbolic links between directories are also supported. Multics is the first to use the now-standard concept of per-<a href="Process_(computing)" title="Process (computing)">process</a> <a href="Stack_(data_structure)" class="mw-redirect" title="Stack (data structure)">stacks</a> in the <a href="Kernel_(operating_system)" title="Kernel (operating system)">kernel</a>, with a separate stack for each security ring. It is also the first to have a <a href="Command_processor" class="mw-redirect" title="Command processor">command processor</a> implemented as ordinary user code – an idea later used in the <a href="Unix_shell" title="Unix shell">Unix shell</a>. It is also one of the first written in a high-level language (Multics <a href="PL/I" title="PL/I">PL/I</a>),<sup id="cite_ref-Mpl1_1-1" class="reference"><a href="#cite_note-Mpl1-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> after the <a href="Burroughs_MCP" title="Burroughs MCP">Burroughs MCP</a> system written in <a href="Executive_Systems_Problem_Oriented_Language" class="mw-redirect" title="Executive Systems Problem Oriented Language">ESPOL</a>, an expanded version of <a href="ALGOL" title="ALGOL">ALGOL</a>.

</p><p>The deployment of Multics into secure computing environments also spurred the development of innovative supporting applications. In 1975, Morrie Gasser of MITRE Corporation developed a pronounceable random word generator to address password requirements of installations such as the Air Force Data Services Center (AFDSC) processing classified information. To avoid guessable passwords, the AFDSC decided to assign passwords but concluded the manual assignment required too much administrative overhead. Thus, a random word generator was researched and then developed in PL/I. Instead of being based on <a href="Phoneme" title="Phoneme">phonemes</a>, the system employed phonemic segments (second order approximations of English) and other rules to enhance pronounceability and randomness, which was statistically modeled against other approaches.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> A descendant of this generator was added to Multics during Project Guardian.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading2"><h2 id="Project_history">Project history</h2></div>

<p>In 1964, Multics was developed initially for the <a href="GE-645" class="mw-redirect" title="GE-645">GE-645</a> mainframe, a <a href="36-bit" class="mw-redirect" title="36-bit">36-bit</a> system. GE's computer business, including Multics, was taken over by Honeywell in 1970; around 1973, Multics was supported on the <a href="Honeywell_6000_series" title="Honeywell 6000 series">Honeywell 6180</a> machines, which included security improvements including hardware support for <a href="Protection_ring" title="Protection ring">protection rings</a>.

</p><p>Bell Labs pulled out of the project in 1969; some of the people who had worked on it there went on to create the <a href="Unix" title="Unix">Unix</a> system. Multics development continued at MIT and General Electric. At MIT in 1975, use of Multics was declining and did not recover by 1976 to prior levels.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> Finally by slashing prices, MIT managed to lure users back to Multics in 1978.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup>

</p><p>In 1974 Honeywell entered into a development contract with the Air Force (with MIT as a sub-contractor) to develop a <a href="Security_kernel" title="Security kernel">security kernel</a> for Multics. This would involve reducing the size of the Multics hardcore by moving specific components of the supervisor out of Ring 0. One of the initial steps after carrying out a security evaluation was the implementation of a <a href="Multilevel_security" title="Multilevel security">multilevel security</a> framework within Multics called AIM (Access Isolation Mechanism). This provided <a href="Mandatory_access_control" title="Mandatory access control">mandatory access control</a> which could be enabled to supplement the already existing <a href="Discretionary_access_control" title="Discretionary access control">discretionary access control</a> that Multics already possessed.<sup id="cite_ref-MDS_18-0" class="reference"><a href="#cite_note-MDS-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup> The resulting Project Guardian ran until termination in 1976; whilst most of its changes were not added to Multics, some parts of the project such as the proposed Secure Front End Processor was productized by Honeywell as SCOMP (Secure Communications Processor).<sup id="cite_ref-scomp_19-0" class="reference"><a href="#cite_note-scomp-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> The SCOMP and its STOP operating system eventually evolved via XTS-200 and XTS-300 into current <a href="XTS-400" title="XTS-400">XTS-400</a> offering of secure operating systems.<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup>

</p><p>Honeywell continued system development until 1985. About 80 multimillion-dollar sites were installed, at universities, industry, and government sites. The French university system had several installations in the early 1980s. After Honeywell stopped supporting Multics, users migrated to other systems, such as Unix.

</p><p>In 1985, Multics was issued certification as a B2 level secure operating system using the <a href="Trusted_Computer_System_Evaluation_Criteria" title="Trusted Computer System Evaluation Criteria">Trusted Computer System Evaluation Criteria</a> from the <a href="National_Computer_Security_Center" class="mw-redirect" title="National Computer Security Center">National Computer Security Center</a> (NCSC), a division of the <a href="NSA" class="mw-redirect" title="NSA">NSA</a>; it was the first operating system evaluated to this level.

</p><p>Multics was distributed from 1975 to 2000 by <a href="Groupe_Bull" title="Groupe Bull">Groupe Bull</a> in <a href="Europe" title="Europe">Europe</a>, and by Bull HN Information Systems Inc. in the United States. In 2006, <a href="Groupe_Bull" title="Groupe Bull">Bull SAS</a> released the source code of Multics versions MR10.2, MR11.0, MR12.0, MR12.1, MR12.2, MR12.3, MR12.4 & MR12.5 under a <a href="Free_software" title="Free software">free software</a> license.<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup>

</p><p>The last known Multics installation running <a href="Native_(computing)" title="Native (computing)">natively</a> on Honeywell hardware was shut down on October 30, 2000, at the Canadian <a href="Department_of_National_Defence_(Canada)" title="Department of National Defence (Canada)">Department of National Defence</a> in Halifax, Nova Scotia, Canada.<sup id="cite_ref-urlMultics_Dates_22-0" class="reference"><a href="#cite_note-urlMultics_Dates-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading3"><h3 id="Current_status">Current status</h3></div>

<p>In 2006 Bull HN released the source code for MR12.5, the final 1992 Multics release, to MIT.<sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> Most of the system is now available as <a href="Free_software" title="Free software">free software</a> with the exception of some optional pieces such as <a href="TCP/IP" class="mw-redirect" title="TCP/IP">TCP/IP</a>.<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup>

</p><p>In 2014, Multics was successfully run on current hardware using an emulator created by Multicians Harry Reed and Charles Anthony.<sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> The 1.0 release of the emulator is available as of 2017.<sup id="cite_ref-26" class="reference"><a href="#cite_note-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> Release 12.6f of Multics accompanies the 1.0 release of the emulator, and adds a few new features, including command line recall and editing using the video system.<sup id="cite_ref-27" class="reference"><a href="#cite_note-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading2"><h2 id="Commands">Commands</h2></div>

<p>The following is a list of programs and <a href="Command_(computing)" title="Command (computing)">commands</a><sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> for common computing tasks that are supported by the Multics <a href="Command-line_interface" title="Command-line interface">command-line interface</a>.<sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-multics-commands_30-0" class="reference"><a href="#cite_note-multics-commands-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup>

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<div class="mw-heading mw-heading3"><h3 id="File_and_directory_access_commands">File and directory access commands</h3></div>

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</style><span class="monospaced"><a href="Cd_(command)" title="Cd (command)">change_wdir</a></span> (<span class="monospaced">cwd</span>) - change the <a href="Working_directory" title="Working directory">working directory</a></li>

<li><span class="monospaced"><a href="Mkdir" title="Mkdir">create_dir</a></span> (<span class="monospaced">cd</span>) - create a directory</li>

<li><span class="monospaced"><a href="Copy_(command)" title="Copy (command)">copy</a></span> (<span class="monospaced">cp</span>) - copy files</li>

<li><span class="monospaced"><a href="Ls" title="Ls">list</a></span> (<span class="monospaced">ls</span>) - list files and directories</li>

<li><span class="monospaced"><a href="Cat_(Unix)" title="Cat (Unix)">print</a></span> (<span class="monospaced">pr</span>) - print the contents of a text file</li>

<li><span class="monospaced"><a href="Pwd" title="Pwd">print_wdir</a></span> (<span class="monospaced">pwd</span>) - print the <a href="Working_directory" title="Working directory">working directory</a></li>

<li><span class="monospaced"><a href="Mv_(Unix)" title="Mv (Unix)">move</a></span> (<span class="monospaced">mv</span>) - move a file or directory to a different directory</li>

<li><span class="monospaced">rename</span> (<span class="monospaced">rn</span>) - rename a file without moving it</li></ul>

<div class="mw-heading mw-heading3"><h3 id="Text_editors">Text editors</h3></div>

<ul><li><span class="monospaced">edm</span> - a simple <a href="Line_editor" title="Line editor">line editor</a></li>

<li><span class="monospaced">emacs</span> - <a href="Multics_Emacs" title="Multics Emacs">Multics Emacs</a></li>

<div class="mw-heading mw-heading3"><h3 id="Document_formatters">Document formatters</h3></div>

<ul><li><span class="monospaced"><a href="TYPSET_and_RUNOFF#Multics" title="TYPSET and RUNOFF">runoff</a></span> (<span class="monospaced">rf</span>)</li></ul>

<div class="mw-heading mw-heading3"><h3 id="Compilers,_assemblers,_and_interpreters">Compilers, assemblers, and interpreters</h3></div>

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<li><span class="monospaced"><a href="BASIC" title="BASIC">basic</a></span></li>

<li><span class="monospaced"><a href="COBOL" title="COBOL">cobol</a></span></li>

<li><span class="monospaced"><a href="Fortran" title="Fortran">fortran</a></span> (<span class="monospaced">ft</span>)</li>

<li><span class="monospaced"><a href="Pascal_(programming_language)" title="Pascal (programming language)">pascal</a></span></li>

</div>

<div class="mw-heading mw-heading3"><h3 id="Email">Email</h3></div>

</div>

<div class="mw-heading mw-heading3"><h3 id="On-line_documentation">On-line documentation</h3></div>

</div>

<div class="mw-heading mw-heading3"><h3 id="Scripting">Scripting</h3></div>

<div class="mw-heading mw-heading3"><h3 id="Data_processing">Data processing</h3></div>

<ul><li><span class="monospaced">gcos</span> (<span class="monospaced">gc</span>) - simulator to run <a href="General_Comprehensive_Operating_System" title="General Comprehensive Operating System">GCOS</a> programs</li>

<li><span class="monospaced">sort</span>, <span class="monospaced">merge</span> - sorting and merging of text and binary files</li></ul>

<div class="mw-heading mw-heading3"><h3 id="Login_sessions">Login sessions</h3></div>

<ul><li><span class="monospaced"><a href="Logout_(command)" class="mw-redirect" title="Logout (command)">logout</a></span></li>

<div class="mw-heading mw-heading3"><h3 id="Active_functions">Active functions</h3></div>

<p>The Multics <a href="Shell_(computing)" title="Shell (computing)">shell</a> language supports "active functions", which are similar to commands, but which return a string value. An active function is called by putting the active function name and the arguments to the active function in square brackets <span class="monospaced">[</span> and <span class="monospaced">]</span>. The string returned by the active function is substituted into the command in place of the call to the active function. For example, when the command <span class="monospaced">echo [working_dir]</span> is processed, the active function <span class="monospaced">working_dir</span> is run; it returns the full path of the <a href="Working_directory" title="Working directory">working directory</a>, which is substituted into the command, so that the <span class="monospaced">echo</span> command prints the working directory.

</p><p>Some programs can act either as commands or as active functions; when run as a command, its result is printed, and when run as an active function, its result is returned as a string.<sup id="cite_ref-multics-commands_30-1" class="reference"><a href="#cite_note-multics-commands-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup>

</p><p>Some common active functions are:

</p>

<ul><li><span class="monospaced"><a href="Floor_and_ceiling_functions" title="Floor and ceiling functions">ceil</a></span> - returns the smallest integer greater than or equal to the argument</li>

<li><span class="monospaced"><a href="Floor_and_ceiling_functions" title="Floor and ceiling functions">floor</a></span> - returns the largest integer less than or equal to the argument</li>

<li><span class="monospaced">home_dir</span> (<span class="monospaced">hd</span>) - returns the <a href="Home_directory" title="Home directory">home directory</a></li>

<li><span class="monospaced"><a href="Ltrim" class="mw-redirect" title="Ltrim">ltrim</a></span></li>

<li><span class="monospaced"><a href="Rtrim" class="mw-redirect" title="Rtrim">rtrim</a></span></li>

<li><span class="monospaced"><a href="Truncation" title="Truncation">trunc</a></span> - returns the integer part of the argument</li>

<li><span class="monospaced">working_dir</span> (<span class="monospaced">wd</span>) - returns the <a href="Working_directory" title="Working directory">working directory</a></li></ul>

<div class="mw-heading mw-heading2"><h2 id="Retrospective_observations">Retrospective observations</h2></div>

<p><a href="Peter_H._Salus" title="Peter H. Salus">Peter H. Salus</a>, author of a book covering Unix's early years,<sup id="cite_ref-Salus_32-0" class="reference"><a href="#cite_note-Salus-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup> stated one position: "With Multics they tried to have a much more versatile and flexible operating system, and it failed miserably".<sup id="cite_ref-bbc-40yr-8205976_33-0" class="reference"><a href="#cite_note-bbc-40yr-8205976-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> This position, however, is said to have been discredited in the computing community because many of Multics' technical innovations are used in modern commercial computing systems.<sup id="cite_ref-Myths_about_Multics_7-1" class="reference"><a href="#cite_note-Myths_about_Multics-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup>

</p><p>The permanently resident kernel of Multics, a system derided in its day as being too large and complex, was 135 KB of code. The first <a href="MIT" class="mw-redirect" title="MIT">MIT</a> <a href="GE_645" title="GE 645">GE-645</a> had 512 kilowords of memory (2 MiB), a truly enormous amount at the time, and the kernel used a moderate portion of Multics main memory.

</p><p>The entire system, including the operating system and the complex PL/I <a href="Compiler" title="Compiler">compiler</a>, user commands, and subroutine libraries, consists of about 1500 source modules. These average roughly 200 lines of source code each, and compile to a total of roughly 4.5 MiB of procedure code, which was fairly large by the standards of the day.

</p><p>Multics compilers generally optimise more for <a href="Code_density" class="mw-redirect" title="Code density">code density</a> than CPU performance, for example using small sub-routines called <i>operators</i> for short standard code sequences, which makes comparison of object code size with modern systems less useful. High code density is a good optimisation choice for Multics as a <a href="Multi-user" class="mw-redirect" title="Multi-user">multi-user</a> system with expensive main memory.

</p><p>During its commercial product history, it was often commented internally that the Honeywell Information Systems (HIS) (later Honeywell-Bull) sales and marketing staff were more familiar with and comfortable making the business case for Honeywell's other computer line, the <a href="Honeywell_Level_6" title="Honeywell Level 6">DPS 6</a> running <a href="General_Comprehensive_Operating_System" title="General Comprehensive Operating System">GCOS</a>. The DPS-6 and GCOS was a well-regarded and reliable platform for inventory, accounting, word processing, and vertical market applications, such as banking, where it had a sizeable customer base. In contrast, the full potential of Multics’ flexibility for even mundane tasks was not easy to comprehend in that era and its features were generally outside the skill set of contemporary business analysts. The scope of this disconnect was concretized by an anecdote conveyed by Paul Stachour, CNO/CSC:

</p>

When American Telephone and Telegraph was changing its name to just AT&T in 1983, a staffer from Honeywell’s legal department showed up and asked a Multician if he could arrange to have the name changed in all of their computerized documents. When asked when the process could be completed, the Multician replied, "It's done." The staffer repeated that he needed <i>hundreds perhaps thousands</i> of documents updated. The Multician explained that he had executed a global search and replace as the staffer was speaking, and the task was in fact completed.</p></blockquote>

<div class="mw-heading mw-heading2"><h2 id="Influence_on_other_projects">Influence on other projects</h2></div>

<p>The design and features of Multics influenced the <a href="Unix" title="Unix">Unix</a> operating system, which was originally written by two Multics programmers, <a href="Ken_Thompson" title="Ken Thompson">Ken Thompson</a> and <a href="Dennis_Ritchie" title="Dennis Ritchie">Dennis Ritchie</a>.<sup id="cite_ref-Seibel_34-0" class="reference"><a href="#cite_note-Seibel-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> Influence of Multics on Unix is evident in many areas, including the <a href="Hierarchical_file_system" title="Hierarchical file system">hierarchical file system</a>, <a href="Redirection_(computing)" title="Redirection (computing)">redirection</a>, the <a href="Shell_(computing)" title="Shell (computing)">shell</a>, and the naming of some commands. But the internal design philosophy is quite different, focusing on keeping the system small and simple, and so correcting some perceived deficiencies of Multics because of its high resource demands on the limited computer hardware of the time.

</p><p>The name <i>Unix</i> (originally <i>Unics</i>) is itself a <a href="Pun" title="Pun">pun</a> on <i>Multics</i>. The <i>U</i> in Unix is rumored to stand for <i><a href="https://en.wiktionary.org/wiki/uniplex" class="extiw external" title="wikt:uniplex">uniplexed</a></i> as opposed to the <i><a href="https://en.wiktionary.org/wiki/multiplex" class="extiw external" title="wikt:multiplex">multiplexed</a></i> of Multics, further underscoring the designers' rejections of Multics' complexity in favor of a more straightforward and workable approach for smaller computers. (Garfinkel and Abelson<sup id="cite_ref-35" class="reference"><a href="#cite_note-35"><span class="cite-bracket">[</span>35<span class="cite-bracket">]</span></a></sup> cite an alternative origin: Peter Neumann at Bell Labs, watching a demonstration of the prototype, suggested the pun name UNICS – pronounced "<a href="Eunuchs" class="mw-redirect" title="Eunuchs">eunuchs</a>" – as a "castrated Multics", although Dennis Ritchie is said to have denied this.<sup id="cite_ref-36" class="reference"><a href="#cite_note-36"><span class="cite-bracket">[</span>36<span class="cite-bracket">]</span></a></sup>)

</p><p>Ken Thompson, in a transcribed 2007 interview with Peter Seibel<sup id="cite_ref-Seibel_34-1" class="reference"><a href="#cite_note-Seibel-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> refers to Multics as "overdesigned and overbuilt and over everything. It was close to unusable. They [Massachusetts Institute of Technology] still claim it's a monstrous success, but it just clearly wasn't". On the influence of Multics on Unix, Thompson stated that "the things that I liked enough (about Multics) to actually take were the hierarchical file system and the shell — a separate process that you can replace with some other process".

</p><p>Dennis Ritchie wrote that the design of UNIX was influenced by <a href="Compatible_Time-Sharing_System" title="Compatible Time-Sharing System">CTSS</a>.<sup id="cite_ref-37" class="reference"><a href="#cite_note-37"><span class="cite-bracket">[</span>37<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading3"><h3 id="Other_operating_systems">Other operating systems</h3></div>

<p>The <a href="Prime_Computer" title="Prime Computer">Prime Computer</a> operating system, <a href="PRIMOS" title="PRIMOS">PRIMOS</a>, was referred to as "Multics in a shoebox" by <a href="William_Poduska" title="William Poduska">William Poduska</a>, a founder of the company. Poduska later moved on to found <a href="Apollo_Computer" title="Apollo Computer">Apollo Computer</a>, whose AEGIS and later <a href="Domain/OS" title="Domain/OS">Domain/OS</a> operating systems, sometimes called "Multics in a matchbox", extends the Multics design to a networked graphics workstation environment.

</p><p>The <a href="Stratus_VOS" title="Stratus VOS">Stratus VOS</a> operating system of Stratus Computer (now <a href="Stratus_Technologies" title="Stratus Technologies">Stratus Technologies</a>) is very strongly influenced by Multics, and both its external user interface and internal structure bear many close resemblances to the older project. The high-reliability, availability, and security features of Multics are extended in Stratus VOS to support a new line of <a href="Fault_tolerant" class="mw-redirect" title="Fault tolerant">fault tolerant</a> computer systems supporting secure, reliable <a href="Transaction_processing" title="Transaction processing">transaction processing</a>. Stratus VOS is the most directly related descendant of Multics still in active development and production usage today.

</p><p><a href="General_Motors" title="General Motors">General Motors</a>' <a href="Multiple_Console_Time_Sharing_System" title="Multiple Console Time Sharing System">Multiple Console Time Sharing System</a> (MCTS) for the <a href="Control_Data_Corporation" title="Control Data Corporation">Control Data Corporation</a> <a href="CDC_STAR-100" title="CDC STAR-100">STAR-100</a> computer was based on Multics.

</p><p>The protection architecture of Multics, restricting the ability of code at one level of the system to access resources at another, was adopted as the basis for the security features of <a href="International_Computers_Limited" title="International Computers Limited">ICL</a>'s <a href="ICL_VME" title="ICL VME">VME</a> operating system.

</p><p>The <a href="Edinburgh_Multiple_Access_System" title="Edinburgh Multiple Access System">Edinburgh Multiple Access System</a> (EMAS) draws particularly on the one-level store concept used by Multics, providing access to files only by mapping them into memory. All memory space is associated with a segment.

</p>

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<ul><li><a href="Time-sharing_system_evolution" title="Time-sharing system evolution">Time-sharing system evolution</a></li>

<li><a href="Peter_J._Denning" title="Peter J. Denning">Peter J. Denning</a></li>

<li><a href="Jack_B._Dennis" class="mw-redirect" title="Jack B. Dennis">Jack B. Dennis</a></li>

<li><a href="Robert_Fano" title="Robert Fano">Robert Fano</a> – director of Project MAC at MIT (1963–1968)</li>

<li><a href="Robert_M._Graham_(computer_scientist)" title="Robert M. Graham (computer scientist)">Robert M. Graham (computer scientist)</a></li>

<li><a href="J._C._R._Licklider" title="J. C. R. Licklider">J. C. R. Licklider</a> – director of Project MAC at MIT (1968–1971)</li>

<li><a href="Peter_G._Neumann" title="Peter G. Neumann">Peter G. Neumann</a></li>

<li><a href="Elliott_Organick" title="Elliott Organick">Elliott Organick</a></li>

<li><a href="Louis_Pouzin" title="Louis Pouzin">Louis Pouzin</a> – introduced the term <i>shell</i> for the command language used in Multics</li>

<li><a href="Jerome_H._Saltzer" class="mw-redirect" title="Jerome H. Saltzer">Jerome H. Saltzer</a></li>

<li><a href="Roger_R._Schell" title="Roger R. Schell">Roger R. Schell</a></li>

<li><a href="Glenda_Schroeder" title="Glenda Schroeder">Glenda Schroeder</a> – implemented the first <a href="Command_line" class="mw-redirect" title="Command line">command line</a> <a href="User_interface" title="User interface">user interface</a> <a href="Shell_(computing)" title="Shell (computing)">shell</a> and proposed the first <a href="Email" title="Email">email</a> system with Pouzin and Crisman</li>

<li><a href="Victor_A._Vyssotsky" title="Victor A. Vyssotsky">Victor A. Vyssotsky</a></li></ul>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

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<li id="cite_note-Mpl1-1"><span class="mw-cite-backlink">^ <a href="#cite_ref-Mpl1_1-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Mpl1_1-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">R. A. Freiburghouse, <a rel="nofollow" class="external text" href="http://www.multicians.org/pl1-raf.html">"The Multics PL/1 Compiler"</a>, General Electric Company, Cambridge, Massachusetts, 1969.</span>

</li>

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</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://opensource.org/licenses/Multics">"Multics License (Multics) - Open Source Initiative"</a>. <i>opensource.org</i>. February 5, 2008<span class="reference-accessdate">. Retrieved <span class="nowrap">April 11,</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-myths-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-myths_3-0">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.multicians.org/myths.html#source">"Myths about Multics"</a>. <i>www.multicians.org</i><span class="reference-accessdate">. Retrieved <span class="nowrap">April 11,</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-Ritchie84-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-Ritchie84_4-0">^</a></b></span> <span class="reference-text">Dennis M. Ritchie, "The Evolution of the Unix Time-sharing System", Communications of the ACM, Vol. 17, 1984, pp. 365-375.</span>

</li>

<li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><cite id="CITEREFDan_Murphy1996" class="citation web cs1">Dan Murphy (1996) [1989]. <a rel="nofollow" class="external text" href="http://tenex.opost.com/hbook.html">"Origins and Development of TOPS-20"</a>.</cite></span>

</li>

<li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><cite id="CITEREFGregory2018" class="citation book cs1">Gregory, Nathan (May 2018). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=kn9eDwAAQBAJ&q=page%2066"><i>The Tym Before</i></a>. Lulu.com. p. 66. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>9781387824755</bdi><span class="reference-accessdate">. Retrieved <span class="nowrap">March 29,</span> 2020</span>.</cite></span>

</li>

<li id="cite_note-Myths_about_Multics-7"><span class="mw-cite-backlink">^ <a href="#cite_ref-Myths_about_Multics_7-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Myths_about_Multics_7-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.multicians.org/myths.html">"Myths about Multics"</a>. <i>www.multicians.org</i><span class="reference-accessdate">. Retrieved <span class="nowrap">April 11,</span> 2018</span>.</cite></span>

</li>

<li id="cite_note-JHSProt-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-JHSProt_8-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFSaltzer1974" class="citation report cs1">Saltzer, Jerome H. (February 1974). <a rel="nofollow" class="external text" href="https://web.mit.edu/Saltzer/www/publications/TRs+TMs/Multics/TR-123.pdf">"Protection and the Control of Information Sharing in Multics"</a> <span class="cs1-format">(PDF)</span>. Introduction to Multics", MAC TR-123 (Report). Cambridge, MA: Massachusetts Institute of Technology and Honeywell Information Systems Inc. pp. <span class="nowrap">2–</span>41<span class="reference-accessdate">. Retrieved <span class="nowrap">March 16,</span> 2022</span>.</cite></span>

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<li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><cite id="CITEREFTom_Van_Vleck2002" class="citation web cs1"><a href="Tom_Van_Vleck" title="Tom Van Vleck">Tom Van Vleck</a> (2002). <a rel="nofollow" class="external text" href="http://www.multicians.org/security.html">"How the Air Force cracked Multics Security"</a>.</cite></span>

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<li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.multicians.org/mgf.html#filesystem">"Multics Glossary -F-"</a>. <i>www.multicians.org</i><span class="reference-accessdate">. Retrieved <span class="nowrap">April 11,</span> 2018</span>.</cite></span>

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<li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text">R. C. Daley and P. G. Neumann, <a rel="nofollow" class="external text" href="http://dl.acm.org/citation.cfm?id=1463915">"A general-purpose file system for secondary storage"</a>, AFIPS '65 (Fall, part I) Proceedings of the November 30 – December 1, 1965</span>

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<li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://lwn.net/Articles/881431/">Brian Kernighan on the origins of Unix</a> LWN.net. 2022.</span>

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<li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://apps.dtic.mil/sti/pdfs/ADA017676.pdf">"A Random Word Generator for Pronounceable Passwords"</a> <span class="cs1-format">(PDF)</span>. Bedford, MA: Electronic Systems Division, Air Force Systems Command, USAF. November 1975. ESD-TR-75-97. <a rel="nofollow" class="external text" href="https://web.archive.org/web/20220408145811/https://apps.dtic.mil/sti/pdfs/ADA017676.pdf">Archived</a> <span class="cs1-format">(PDF)</span> from the original on April 8, 2022<span class="reference-accessdate">. Retrieved <span class="nowrap">March 8,</span> 2021</span>.</cite></span>

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<li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><cite id="CITEREFVan_Vleck" class="citation web cs1">Van Vleck, Tom. <a rel="nofollow" class="external text" href="https://multicians.org/thvv/gpw-js.html">"Password Generator"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">March 8,</span> 2021</span>.</cite></span>

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<li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><cite class="citation journal cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20220413015059/https://libraries.mit.edu/archives/mithistory/presidents-reports/1975.pdf">"Report of the President"</a> <span class="cs1-format">(PDF)</span>. <i>Massachusetts Institute of Technology Bulletin</i>. <b>111</b> (4): 355. December 1975. Archived from <a rel="nofollow" class="external text" href="https://libraries.mit.edu/archives/mithistory/presidents-reports/1975.pdf">the original</a> <span class="cs1-format">(PDF)</span> on April 13, 2022<span class="reference-accessdate">. Retrieved <span class="nowrap">April 12,</span> 2022</span>. <q>Use of the Multics service, operated on the Honeywell 6180 system, declined...a decrease of 15 percent.</q></cite></span>

</li>

<li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><cite class="citation journal cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20220413015059/https://libraries.mit.edu/archives/mithistory/presidents-reports/1975.pdf">"Report of the President"</a> <span class="cs1-format">(PDF)</span>. <i>Massachusetts Institute of Technology Bulletin</i>. <b>112</b> (4): 392. November 1976. Archived from <a rel="nofollow" class="external text" href="https://libraries.mit.edu/archives/mithistory/presidents-reports/1975.pdf">the original</a> <span class="cs1-format">(PDF)</span> on April 13, 2022<span class="reference-accessdate">. Retrieved <span class="nowrap">April 12,</span> 2022</span>. <q>... the demise of several Multics projects which failed to obtain funding.</q></cite></span>

</li>

<li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20220413021106/https://libraries.mit.edu/archives/mithistory/presidents-reports/1978.pdf">"Report of the President and the Chancellor"</a> <span class="cs1-format">(PDF)</span>. Massachusetts Institute of Technology. 1978. p. 450. Archived from <a rel="nofollow" class="external text" href="https://libraries.mit.edu/archives/mithistory/presidents-reports/1978.pdf">the original</a> <span class="cs1-format">(PDF)</span> on April 13, 2022<span class="reference-accessdate">. Retrieved <span class="nowrap">April 12,</span> 2022</span>. <q>This new pricing proved so attractive to many people, however, that Multics users and usage increased considerably.</q></cite></span>

</li>

<li id="cite_note-MDS-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-MDS_18-0">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://multicians.org/multics-data-security.html">"Multics Data Security"</a>. <i>multicians.org</i>.</cite></span>

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<li id="cite_note-scomp-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-scomp_19-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFFraim1983" class="citation journal cs1">Fraim, Lester J. (July 1983). "Scomp: A Solution to the Multilevel Security Problem". <i>Computer</i>. <b>16</b> (7): <span class="nowrap">26–</span>34. <a href="Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1109%2FMC.1983.1654440">10.1109/MC.1983.1654440</a>.</cite></span>

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<li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.commoncriteriaportal.org/files/epfiles/BAE%20STOP%207%20Security%20Target%201.08.pdf">"STOP OS™ Version 7.3.1 Security Target"</a> <span class="cs1-format">(PDF)</span>. Common Criteria.</cite></span>

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<li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://stuff.mit.edu/afs/athena/reference/multics-history/">"Multics"</a>. <i>stuff.mit.edu</i><span class="reference-accessdate">. Retrieved <span class="nowrap">July 25,</span> 2022</span>.</cite></span>

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<li id="cite_note-urlMultics_Dates-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-urlMultics_Dates_22-0">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.multicians.org/chrono.html">"Multics History Dates"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">September 13,</span> 2015</span>. <q>Shutdown of DND-H (17:08Z 10/30/00)</q></cite></span>

</li>

<li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"><cite id="CITEREFVan_Vleck" class="citation web cs1">Van Vleck, Tom. <a rel="nofollow" class="external text" href="http://web.mit.edu/multics-history/#community">"Open Source for Multics"</a>. <i>Multicians.org</i><span class="reference-accessdate">. Retrieved <span class="nowrap">April 11,</span> 2016</span>.</cite></span>

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<li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text"><cite id="CITEREFAnthony" class="citation web cs1">Anthony, Charles. <a rel="nofollow" class="external text" href="https://sourceforge.net/p/dps8m/mailman/message/34310157/">"(email) Re: [dps8m-developers] Multiprocessor and/or networked Multics"</a>. <i>Sourceforge.net</i><span class="reference-accessdate">. Retrieved <span class="nowrap">April 11,</span> 2016</span>.</cite></span>

</li>

<li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://ringzero.wikidot.com/start">"RingZero - Multics reborn"</a>. <i>WikidotCom</i><span class="reference-accessdate">. Retrieved <span class="nowrap">April 11,</span> 2015</span>.</cite></span>

</li>

<li id="cite_note-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-26">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://multicians.org/simulator.html">"Multics Simulator"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">July 9,</span> 2017</span>.</cite></span>

</li>

<li id="cite_note-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-27">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://multics-wiki.swenson.org/index.php/Main_Page#Installing_Multics">"Installing Multics"</a><span class="reference-accessdate">. Retrieved <span class="nowrap">May 19,</span> 2020</span>.</cite></span>

</li>

<li id="cite_note-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-28">^</a></b></span> <span class="reference-text"><cite id="CITEREFHoneywell_Bull,_Inc.1985" class="citation book cs1">Honeywell Bull, Inc. (February 1985). <a rel="nofollow" class="external text" href="http://www.bitsavers.org/pdf/honeywell/large_systems/multics/AG92-06B_multicsCmds_Nov87.pdf"><i>Multics Commands and Active Functions (AG92-06)</i></a> <span class="cs1-format">(PDF)</span><span class="reference-accessdate">. Retrieved <span class="nowrap">March 30,</span> 2023</span>.</cite></span>

</li>

<li id="cite_note-29"><span class="mw-cite-backlink"><b><a href="#cite_ref-29">^</a></b></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.multicians.org/unix.html">"Unix and Multics"</a>.</cite></span>

</li>

<li id="cite_note-multics-commands-30"><span class="mw-cite-backlink">^ <a href="#cite_ref-multics-commands_30-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-multics-commands_30-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.multicians.org/multics-commands.html">"Multics Commands"</a>.</cite></span>

</li>

<li id="cite_note-31"><span class="mw-cite-backlink"><b><a href="#cite_ref-31">^</a></b></span> <span class="reference-text"><cite class="citation book cs1"><a rel="nofollow" class="external text" href="https://bitsavers.org/pdf/honeywell/large_systems/multics/HH07-01_C_UsersGuide_Nov87.pdf"><i>Multics C User's Guide</i></a> <span class="cs1-format">(PDF)</span>. Honeywell Bull. November 1987<span class="reference-accessdate">. Retrieved <span class="nowrap">March 26,</span> 2024</span>.</cite></span>

</li>

<li id="cite_note-Salus-32"><span class="mw-cite-backlink"><b><a href="#cite_ref-Salus_32-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFSalus1994" class="citation book cs1">Salus, Peter H. (1994). <i>A quarter century of UNIX</i> (Reprinted with corrections Jan. 1995. ed.). Reading, Mass.: Addison-Wesley Pub. Co. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-0-201-54777-1</bdi>.</cite></span>

</li>

<li id="cite_note-bbc-40yr-8205976-33"><span class="mw-cite-backlink"><b><a href="#cite_ref-bbc-40yr-8205976_33-0">^</a></b></span> <span class="reference-text"><cite id="CITEREFWard2009" class="citation news cs1">Ward, Mark (August 20, 2009). <a rel="nofollow" class="external text" href="http://news.bbc.co.uk/2/hi/technology/8205976.stm">"40 years of Unix"</a>. <i>BBC News</i><span class="reference-accessdate">. Retrieved <span class="nowrap">April 27,</span> 2010</span>.</cite> Quoting Peter Salus.</span>

</li>

<li id="cite_note-Seibel-34"><span class="mw-cite-backlink">^ <a href="#cite_ref-Seibel_34-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-Seibel_34-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text">Peter Seibel. <a href="Coders_at_Work" title="Coders at Work">Coders at Work</a>: Reflections on the Craft of Programming. APress Publications, 2007. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-1-4302-1948-4</bdi></span>

</li>

<li id="cite_note-35"><span class="mw-cite-backlink"><b><a href="#cite_ref-35">^</a></b></span> <span class="reference-text">Garfinkel, Simson and Abelson, Harold. Architects of the Information Society: Thirty-Five Years of the Laboratory for Computer Science at MIT. MIT Press, 1999. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-0262071963</bdi></span>

</li>

<li id="cite_note-36"><span class="mw-cite-backlink"><b><a href="#cite_ref-36">^</a></b></span> <span class="reference-text"><cite id="CITEREFKarn,_Phil1981" class="citation newsgroup cs1">Karn, Phil (October 28, 1981). <a rel="nofollow" class="external text" href="http://article.olduse.net/4743@Aucbvax.UUCP">"Origins of unix"</a>. <a href="Usenet_newsgroup" title="Usenet newsgroup">Newsgroup</a>: <a rel="nofollow" class="external text" href="news:fa.unix-wizards">fa.unix-wizards</a>. <a href="Usenet_(identifier)" class="mw-redirect" title="Usenet (identifier)">Usenet:</a> <a rel="nofollow" class="external text" href="news:4743@Aucbvax.UUCP">4743@Aucbvax.UUCP</a><span class="reference-accessdate">. Retrieved <span class="nowrap">April 11,</span> 2014</span>.</cite></span>

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<li id="cite_note-37"><span class="mw-cite-backlink"><b><a href="#cite_ref-37">^</a></b></span> <span class="reference-text"><cite id="CITEREFRitchie1977" class="citation conference cs1"><a href="Dennis_Ritchie" title="Dennis Ritchie">Ritchie, Dennis M.</a> (1977). <a rel="nofollow" class="external text" href="https://www.bell-labs.com/usr/dmr/www/retro.pdf"><i>The Unix Time-sharing System: A retrospective</i></a> <span class="cs1-format">(PDF)</span>. Tenth Hawaii International Conference on the System Sciences. <q>a good case can be made that UNIX is in essence a modern implementation of MIT's CTSS system</q></cite></span>

</li>

</ol></div>

<div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2></div>

<p>The literature contains a large number of papers about Multics, and various components of it; a fairly complete list is available at the <a rel="nofollow" class="external text" href="http://www.multicians.org/biblio.html">Multics Bibliography</a> page and on a second, briefer <a rel="nofollow" class="external text" href="http://web.mit.edu/srz/www/multics-bibliography.html">1994 Multics bibliography</a> (text format). The most important and/or informative ones are listed below.

</p>

<ul><li><a href="Fernando_J._Corbat%C3%B3" title="Fernando J. Corbató">F. J. Corbató</a>, <a href="Michael_Schroeder" title="Michael Schroeder">V. A. Vyssotsky</a>, <a rel="nofollow" class="external text" href="http://www.multicians.org/fjcc1.html"><i>Introduction and Overview of the Multics System</i></a> (<a href="AFIPS" class="mw-redirect" title="AFIPS">AFIPS</a> 1965) is a good introduction to the system.</li>

<li>F. J. Corbató, C. T. Clingen, <a href="J._H._Saltzer" class="mw-redirect" title="J. H. Saltzer">J. H. Saltzer</a>, <a rel="nofollow" class="external text" href="http://www.multicians.org/f7y.html"><i>Multics – The First Seven Years</i></a> (AFIPS, 1972) is an excellent review, written after a considerable period of use and improvement over the initial efforts.</li>

<li>J. J. Donovan, <a href="Stuart_Madnick" title="Stuart Madnick">S. Madnick</a>, <a rel="nofollow" class="external text" href="http://catalog.loc.gov/cgi-bin/Pwebrecon.cgi?v1=6&ti=1,6&Search_Arg=Donovan%2C%20John%20J.&Search_Code=NAME%40&CNT=100&PID=fahdDtIh7Y1ODWe5X_fO2_UUafeDT&SEQ=20090914123346&SID=1">Operating Systems</a>, is a fundamental read on operating systems.</li>

<li>J. J. Donovan, <a rel="nofollow" class="external text" href="http://catalog.loc.gov/cgi-bin/Pwebrecon.cgi?v1=5&ti=1,5&Search_Arg=Donovan%2C%20John%20J.&Search_Code=NAME%40&CNT=100&PID=fahdDtIh7Y1ODWe5X_fO2_UUafeDT&SEQ=20090914123346&SID=1">Systems Programming</a>, is a good introduction into systems programming and operating systems.</li></ul>

<div class="mw-heading mw-heading3"><h3 id="Technical_details">Technical details</h3></div>

<ul><li><a href="Jerome_H._Saltzer" class="mw-redirect" title="Jerome H. Saltzer">Jerome H. Saltzer</a>, <i><a rel="nofollow" class="external text" href="https://web.archive.org/web/20060918161127/http://www.lcs.mit.edu/publications/specpub.php?id=691">Introduction to Multics</a></i> (MIT Project MAC, 1974) is a considerably longer introduction to the system, geared towards actual users.</li>

<li><a href="Elliott_Organick" title="Elliott Organick">Elliott I. Organick</a>, <i>The Multics System: An Examination of Its Structure</i> (MIT Press, 1972) is the standard work on the system, although it documents an early version, and some features described therein never appeared in the actual system.</li>

<li><a href="Victor_A._Vyssotsky" title="Victor A. Vyssotsky">V. A. Vyssotsky</a>, <a href="Fernando_J._Corbat%C3%B3" title="Fernando J. Corbató">F. J. Corbató</a>, R. M. Graham, <i><a rel="nofollow" class="external text" href="http://www.multicians.org/fjcc3.html">Structure of the Multics Supervisor</a></i> (AFIPS 1965) describes the basic internal structure of the Multics kernel.</li>

<li><a href="Jerome_H._Saltzer" class="mw-redirect" title="Jerome H. Saltzer">Jerome H. Saltzer</a>, <i><a rel="nofollow" class="external text" href="https://web.archive.org/web/20011127053649/http://ncstrl.mit.edu/Dienst/UI/2.0/Describe/ncstrl.mit_lcs/LCS-TR-30?abstract=saltzer">Traffic Control in a Multiplexed Computer System</a></i> (MIT Project MAC, June 1966) is the original description of the idea of switching kernel stacks; one of the classic papers of computer science.</li>

<li>R. C. Daley, <a href="Peter_G._Neumann" title="Peter G. Neumann">P. G. Neumann</a>, <i><a rel="nofollow" class="external text" href="http://www.multicians.org/fjcc4.html">A General Purpose File System for Secondary Storage</a></i> (AFIPS, 1965) describes the file system, including the access control and backup mechanisms.</li>

<li>R. J. Feiertag, E. I. Organick, <i><a rel="nofollow" class="external text" href="http://www.multicians.org/rjf.html">The Multics Input/Output System</a></i>. Describes the lower levels of the I/O implementation.</li>

<li>A. Bensoussan, C. T. Clingen, R. C. Daley, <i><a rel="nofollow" class="external text" href="http://www.multicians.org/multics-vm.html">The Multics Virtual Memory: Concepts and Design</a></i>, (<a href="Association_for_Computing_Machinery" title="Association for Computing Machinery">ACM</a> <a href="SOSP" class="mw-redirect" title="SOSP">SOSP</a>, 1969) describes the Multics memory system in some detail.</li>

<li><a href="Paul_Green_(engineer)" title="Paul Green (engineer)">Paul Green</a>, <i><a rel="nofollow" class="external text" href="https://web.archive.org/web/20010305133541/http://ftp.stratus.com:80/pub/vos/multics/pg/mvm.html">Multics Virtual Memory – Tutorial and Reflections</a></i> is a good in-depth look at the Multics storage system.</li>

<li><a href="Roger_R._Schell" title="Roger R. Schell">Roger R. Schell</a>, <i>Dynamic Reconfiguration in a Modular Computer System</i> (MIT Project MAC, 1971) describes the reconfiguration mechanisms.</li></ul>

<div class="mw-heading mw-heading3"><h3 id="Security">Security</h3></div>

<ul><li>Paul A. Karger, Roger R. Schell, <i><a rel="nofollow" class="external text" href="http://csrc.nist.gov/publications/history/karg74.pdf">Multics Security Evaluation: Vulnerability Analysis</a></i> (Air Force Electronic Systems Division, 1974) describes the classic attacks on Multics security by a "<a href="Tiger_team" title="Tiger team">tiger team</a>".</li>

<li><a href="Jerome_H._Saltzer" class="mw-redirect" title="Jerome H. Saltzer">Jerome H. Saltzer</a>, Michael D. Schroeder, <i><a rel="nofollow" class="external text" href="http://cap-lore.com/CapTheory/ProtInf/">The Protection of Information in Computer Systems</a></i> (Proceedings of the <a href="IEEE" class="mw-redirect" title="IEEE">IEEE</a>, September 1975) describes the fundamentals behind the first round of security upgrades; another classic paper.</li>

<li><a href="Michael_Schroeder" title="Michael Schroeder">M. D. Schroeder</a>, D. D. Clark, <a href="J._H._Saltzer" class="mw-redirect" title="J. H. Saltzer">J. H. Saltzer</a>, D. H. Wells. <i><a rel="nofollow" class="external text" href="https://web.archive.org/web/20011124185621/http://ncstrl.mit.edu/Dienst/UI/2.0/Describe/ncstrl.mit_lcs/LCS-TR-196?abstract=saltzer">Final Report of the Multics Kernel Design Project</a></i> (MIT LCS, 1978) describes the security upgrades added to produce an even more improved version.</li>

<li>Paul A. Karger, Roger R. Schell, <i><a rel="nofollow" class="external text" href="http://www.acsac.org/2002/papers/classic-multics.pdf">Thirty Years Later: Lessons from the Multics Security Evaluation</a></i> (IBM, 2002) is an interesting retrospective which compares actual deployed security in today's hostile environment with what was demonstrated to be possible decades ago. It concludes that Multics offered considerably stronger security than most systems commercially available in 2002.</li></ul>

<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>

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<div class="side-box-text plainlist">Wikimedia Commons has media related to <span style="font-weight: bold; font-style: italic;"><a href="https://commons.wikimedia.org/wiki/Category:Multics" class="extiw external" title="commons:Category:Multics">Multics</a></span>.</div></div>

</div>

<ul><li><a rel="nofollow" class="external text" href="https://www.multicians.org/">multicians.org</a> is a comprehensive site with a lot of material

<ul><li><a rel="nofollow" class="external text" href="http://www.multicians.org/papers.html">Multics papers online</a></li>

<li><a rel="nofollow" class="external text" href="http://www.multicians.org/mga.html">Multics glossary</a></li>

<li><a rel="nofollow" class="external text" href="http://www.multicians.org/myths.html">Myths</a> discusses numerous myths about Multics in some detail, including the myths that it failed, that it was big and slow, as well as a few understandable misapprehensions</li>

<li><a rel="nofollow" class="external text" href="http://www.multicians.org/security.html">Multics security</a></li>

<li><a rel="nofollow" class="external text" href="http://www.multicians.org/unix.html">Unix and Multics</a></li>

<li><a rel="nofollow" class="external text" href="http://www.multicians.org/general.html">Multics general info and FAQ</a> Includes extensive overview of other software systems influenced by Multics</li></ul></li>

<li><a rel="nofollow" class="external text" href="https://dps8m.gitlab.io/dps8m/">Open source emulator for the GE Large Systems / Honeywell / Bull 600/6000‑series mainframe computers</a></li>

<li><a rel="nofollow" class="external text" href="http://purl.umn.edu/41295">Honeywell, Inc., MULTICS records, 1965–1982</a>. <a href="Charles_Babbage_Institute" class="mw-redirect" title="Charles Babbage Institute">Charles Babbage Institute</a>, University of Minnesota. Multics development records include the second MULTICS System Programmers Manual; MULTICS Technical Bulletins that describe procedures, applications, and problems, especially concerning security; and returned "Request for Comments Forms" that include technical papers and thesis proposals.</li>

<li><a rel="nofollow" class="external text" href="https://swenson.org/multics_wiki/">Current Multics development home page</a></li>

<li><a rel="nofollow" class="external text" href="http://web.mit.edu/multics-history/">Official historical source code archive at MIT</a></li>

<li><a rel="nofollow" class="external text" href="http://webarchive.loc.gov/all/20011130013712/http://www.mit.edu:8001/afs/net/user/srz/www/multics.html">Link page to various Multics information</a> at the <a href="Library_of_Congress" title="Library of Congress">Library of Congress</a> Web Archives (archived 2001-11-30)</li>

<li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20020219203621/http://ftp.stratus.com:80/pub/vos/multics/multics.html">Multics repository at Stratus Computer</a> at the <a href="Wayback_Machine" title="Wayback Machine">Wayback Machine</a> (archived 2002-02-19)</li>

<li><a rel="nofollow" class="external text" href="http://www.vaxman.de/historic_computers/multics/multics.html">Multics at Universitaet Mainz</a></li>

<li><a rel="nofollow" class="external text" href="http://bitsavers.org/pdf/honeywell/large_systems/multics/">Various scanned Multics manuals</a></li>

<li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20210114010400/http://www.cbi.umn.edu/iterations/haigh.html">Multicians.org and the History of Operating Systems</a> at the <a href="Wayback_Machine" title="Wayback Machine">Wayback Machine</a> (archived 2021-01-14), a critical review of Multicians.org, plus a capsule history of Multics.</li></ul>

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</style><div id="Multics174" style="font-size:114%;margin:0 4em"></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Developer</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<li><a href="General_Electric" title="General Electric">General Electric</a></li>

<li><a href="Honeywell" title="Honeywell">Honeywell</a></li>

<li><a href="Groupe_Bull" title="Groupe Bull">Groupe Bull</a></li></ul>

</div></td><td class="noviewer navbox-image" rowspan="5" style="width:1px;padding:0 0 0 2px"><div><span typeof="mw:File"></span></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">People</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="David_D._Clark" title="David D. Clark">David D. Clark</a></li>

<li><a href="Fernando_J._Corbat%C3%B3" title="Fernando J. Corbató">Fernando J. Corbató</a></li>

<li><a href="Monte_Davidoff" title="Monte Davidoff">Monte Davidoff</a></li>

<li><a href="Peter_J._Denning" title="Peter J. Denning">Peter J. Denning</a></li>

<li><a href="Jack_Dennis" title="Jack Dennis">Jack Dennis</a></li>

<li><a href="Stuart_Feldman" title="Stuart Feldman">Stuart Feldman</a></li>

<li><a href="Robert_M._Graham_(computer_scientist)" title="Robert M. Graham (computer scientist)">Robert M. Graham</a></li>

<li><a href="Bernard_Greenberg" title="Bernard Greenberg">Bernard Greenberg</a></li>

<li><a href="Douglas_McIlroy" title="Douglas McIlroy">Douglas McIlroy</a></li>

<li><a href="Robert_Morris_(cryptographer)" title="Robert Morris (cryptographer)">Robert Morris</a></li>

<li><a href="Peter_G._Neumann" title="Peter G. Neumann">Peter G. Neumann</a></li>

<li><a href="Joe_Ossanna" title="Joe Ossanna">Joe Ossanna</a></li>

<li><a href="Michael_A._Padlipsky" title="Michael A. Padlipsky">Michael A. Padlipsky</a></li>

<li><a href="Dennis_Ritchie" title="Dennis Ritchie">Dennis Ritchie</a></li>

<li><a href="Jerry_Saltzer" title="Jerry Saltzer">Jerry Saltzer</a></li>

<li><a href="Glenda_Schroeder" title="Glenda Schroeder">Glenda Schroeder</a></li>

<li><a href="Michael_Schroeder" title="Michael Schroeder">Michael Schroeder</a></li>

<li><a href="Richard_Soley" title="Richard Soley">Richard Soley</a></li>

<li><a href="Ken_Thompson" title="Ken Thompson">Ken Thompson</a></li>

<li><a href="Tom_Van_Vleck" title="Tom Van Vleck">Tom Van Vleck</a></li>

<li><a href="Victor_A._Vyssotsky" title="Victor A. Vyssotsky">Victor A. Vyssotsky</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Software</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Space_Travel_(video_game)" title="Space Travel (video game)">Space Travel</a></li>

<li><a href="Maclisp" title="Maclisp">Maclisp</a></li>

<li><a href="Macsyma" title="Macsyma">Macsyma</a></li>

<li><a href="Multics_Emacs" title="Multics Emacs">Multics Emacs</a></li>

<li><a href="Multics_Relational_Data_Store" title="Multics Relational Data Store">Multics Relational Data Store</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Multics-like<br>systems</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Domain/OS" title="Domain/OS">Domain/OS</a></li>

<li><a href="General_Comprehensive_Operating_System" title="General Comprehensive Operating System">General Comprehensive Operating System</a></li>

<li><a href="GEORGE_(operating_system)" title="GEORGE (operating system)">GEORGE</a></li>

<li><a href="Multiple_Console_Time_Sharing_System" title="Multiple Console Time Sharing System">Multiple Console Time Sharing System</a></li>

<li><a href="PRIMOS" title="PRIMOS">PRIMOS</a></li>

<li><a href="Stratus_VOS" title="Stratus VOS">Stratus VOS</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Project_MAC" class="mw-redirect" title="Project MAC">Project MAC</a></li>

<li><a href="Compatible_Time-Sharing_System" title="Compatible Time-Sharing System">Compatible Time-Sharing System</a> (predecessor)</li></ul>

</div></td></tr><tr><td class="navbox-abovebelow" colspan="3"><div><span class="noviewer" typeof="mw:File"><span title="Category"></span></span> Category</div></td></tr></tbody></table></div>

<div class="navbox-styles"></div><div role="navigation" class="navbox" aria-labelledby="Honeywell85" style="padding:3px"><table class="nowraplinks mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div id="Honeywell85" style="font-size:114%;margin:0 4em"><a href="Honeywell" title="Honeywell">Honeywell</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">People</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Albert_Butz" title="Albert Butz">Albert Butz</a></li>

<li><a href="Darius_Adamczyk" title="Darius Adamczyk">Darius Adamczyk</a></li>

<li><a href="David_M._Cote" title="David M. Cote">David M. Cote</a></li>

<li><a href="Mark_C._Honeywell" title="Mark C. Honeywell">Mark C. Honeywell</a></li>

<li><a href="W._R._Sweatt" title="W. R. Sweatt">W. R. Sweatt</a></li></ul>

</div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th id="Board_of_directors18" scope="row" class="navbox-group" style="width:1%">Board of directors</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Darius_Adamczyk" title="Darius Adamczyk">Darius Adamczyk</a></li>

<li><a href="George_Paz" title="George Paz">George Paz</a></li>

<li><a href="Judd_Gregg" title="Judd Gregg">Judd Gregg</a></li>

<li><a href="Kevin_Burke_(CEO)" class="mw-redirect" title="Kevin Burke (CEO)">Kevin Burke</a></li>

<li><a href="Scott_Davis_(businessman)" title="Scott Davis (businessman)">Scott Davis</a></li></ul>

</div></td></tr></tbody></table><div>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Acquisitions</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="AdvanSix" title="AdvanSix">AdvanSix</a></li>

<li><a href="AlliedSignal" title="AlliedSignal">AlliedSignal</a></li>

<li><a href="Bendix_Corporation" title="Bendix Corporation">Bendix Aviation</a></li>

<li><a href="Bunker_Ramo" title="Bunker Ramo">Bunker Ramo Corporation</a></li>

<li><a href="Fire-Lite_Alarms" title="Fire-Lite Alarms">Fire-Lite Alarms</a></li>

<li><a href="First_Alert" title="First Alert">First Alert</a></li>

<li><a href="Garrett_AiResearch" title="Garrett AiResearch">Garrett AiResearch</a></li>

<li><a href="Honeywell_Gent" title="Honeywell Gent">Honeywell Gent</a></li>

<li><a href="Hand_Held_Products" title="Hand Held Products">Hand Held Products</a></li>

<li><a href="Honeywell_Analytics" title="Honeywell Analytics">Honeywell Analytics</a></li>

<li><a href="Garrett_Motion" title="Garrett Motion">Honeywell Turbo Technologies</a></li>

<li><a href="Honeywell_UOP" title="Honeywell UOP">Honeywell UOP</a></li>

<li><a href="Intelligrated" title="Intelligrated">Intelligrated</a></li>

<li><a href="Intermec" title="Intermec">Intermec</a></li>

<li><a href="King_Radio_(company)" title="King Radio (company)">King Radio</a></li>

<li><a href="Leeds_%26_Northrup" title="Leeds & Northrup">Leeds & Northrup</a></li>

<li><a href="Measurex" title="Measurex">Measurex</a></li>

<li><a href="MK_Electric" title="MK Electric">MK Electric</a></li>

<li><a href="Notifier" title="Notifier">Notifier</a></li>

<li><a href="Novar_Controls" title="Novar Controls">Novar Controls</a></li>

<li><a href="Novar_plc" title="Novar plc">Novar plc</a></li>

<li><a href="Pittway" title="Pittway">Pittway</a></li>

<li><a href="Sperry_Corporation" title="Sperry Corporation">Sperry Corporation</a></li>

<li><a href="System_Sensor" title="System Sensor">System Sensor</a></li>

<li><a href="Xtralis" title="Xtralis">Xtralis</a></li>

<li><a href="EMS_Technologies" title="EMS Technologies">EMS Technologies</a></li>

<li><a href="Hymatic" title="Hymatic">Hymatic</a></li>

<li>Normalair</li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Products</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%"><a href="Honeywell_Aerospace" title="Honeywell Aerospace">Aerospace Technologies</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Airplane_Information_Management_System" title="Airplane Information Management System">Airplane Information Management System</a></li>

<li><a href="Honeywell_auxiliary_power_unit" title="Honeywell auxiliary power unit">Auxiliary power units (APU)</a></li>

<li><a href="Garrett_ATF3" title="Garrett ATF3">Garrett ATF3</a></li>

<li><a href="Garrett_F109" title="Garrett F109">Garrett F109</a></li>

<li><a href="Honeywell_TPE331" title="Honeywell TPE331">Garrett TPE331</a></li>

<li><a href="Honeywell_HTF7000" title="Honeywell HTF7000">Honeywell HTF7000</a></li>

<li><a href="Honeywell_HTS900" title="Honeywell HTS900">Honeywell HTS900</a></li>

<li><a href="Honeywell_Primus" title="Honeywell Primus">Honeywell Primus</a></li>

<li><a href="Honeywell_RQ-16_T-Hawk" title="Honeywell RQ-16 T-Hawk">Honeywell RQ-16 T-Hawk</a></li>

<li><a href="Honeywell/ITEC_F124" title="Honeywell/ITEC F124">Honeywell/ITEC F124</a></li>

<li><a href="Lycoming_ALF_502" title="Lycoming ALF 502">Lycoming ALF 502</a></li>

<li><a href="Lycoming_LTS101" title="Lycoming LTS101">Lycoming LTS101</a></li>

<li><a href="Mark_46_torpedo" title="Mark 46 torpedo">Mark 46 torpedo</a></li>

<li><a href="RUR-5_ASROC" title="RUR-5 ASROC">RUR-5 ASROC</a></li>

<li><a href="Wagtail_(missile)" title="Wagtail (missile)">Wagtail missile</a></li>

<li><a href="Honeywell_FX5" title="Honeywell FX5">Honeywell FX5</a></li>

<li><a href="Garrett_TFE731" title="Garrett TFE731">Garrett TFE731</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Honeywell building technologies</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Honeywell_T87" title="Honeywell T87">Honeywell T87</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Performance materials and technologies</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="2%2C3%2C3%2C3-Tetrafluoropropene" title="2,3,3,3-Tetrafluoropropene">Solstice</a></li>

<li><a href="Spectra_Shield" title="Spectra Shield">Spectra Shield</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Safety and productivity solutions</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Fenzy" title="Fenzy">Fenzy</a></li>

<li><a href="HORTA_(mining)" title="HORTA (mining)">HORTA (mining)</a></li>

<li><a href="Positive_pressure_personnel_suit" title="Positive pressure personnel suit">Positive pressure personnel suit</a></li>

<li><a href="RHPPC" title="RHPPC">RHPPC</a></li>

<li><a href="SPECTRA_helmet" title="SPECTRA helmet">SPECTRA helmet</a></li></ul>

</div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Legacy products</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="DATAmatic_1000" title="DATAmatic 1000">DATAmatic 1000</a></li>

<li><a href="Honeywell_200" title="Honeywell 200">Honeywell 200</a></li>

<li><a href="Honeywell_316" title="Honeywell 316">Honeywell 316</a></li>

<li><a href="Honeywell_6000_series" title="Honeywell 6000 series">Honeywell 6000 series</a></li>

<li><a href="Honeywell_800" title="Honeywell 800">Honeywell 800</a></li>

<li><a href="Honeywell_ARGUS" title="Honeywell ARGUS">Honeywell ARGUS</a></li>

<li><a href="Honeywell_CP-6" title="Honeywell CP-6">Honeywell CP-6</a></li>

<li><a href="Honeywell_Level_6" title="Honeywell Level 6">Honeywell Level 6</a></li>

<li><a href="Garrett_ATF3" title="Garrett ATF3">Garrett ATF3</a></li>

<li><a href="BUNCH" title="BUNCH">BUNCH</a></li>

<li><a href="General_Instrument_CP1600" title="General Instrument CP1600">General Instrument CP1600</a></li>

<li><a href="VIP_terminal" title="VIP terminal">VIP terminal</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Facilities</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="Honeywell_Uranium_Hexafluoride_Processing_Facility" title="Honeywell Uranium Hexafluoride Processing Facility">Honeywell Uranium Hexafluoride Processing Facility</a></li>

<li><a href="Kansas_City_National_Security_Campus" title="Kansas City National Security Campus">Kansas City Plant</a></li>

<li><a href="Sandia_National_Laboratories" title="Sandia National Laboratories">Sandia National Laboratories</a></li></ul>

</div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Joint ventures</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="ConverDyn" title="ConverDyn">ConverDyn</a></li></ul>

<ul><li><i><a href="Honeywell%2C_Inc._v._Sperry_Rand_Corp." title="Honeywell, Inc. v. Sperry Rand Corp.">Honeywell, Inc. v. Sperry Rand Corp.</a></i></li>

<li><a href="Advanced_Turbine_Engine_Company" title="Advanced Turbine Engine Company">Advanced Turbine Engine Company</a></li>

<li><a href="Honeywell_Project" title="Honeywell Project">Honeywell Project</a></li>

<li><a href="International_Turbine_Engine_Company" title="International Turbine Engine Company">International Turbine Engine Company</a></li>

<li><a href="List_of_Honeywell_products_and_services" title="List of Honeywell products and services">List of Honeywell products and services</a></li>

<li><a href="Terminal_High_Altitude_Area_Defense" title="Terminal High Altitude Area Defense">Terminal High Altitude Area Defense</a></li></ul>

</div></td></tr></tbody></table></div>

<div class="navbox-styles"></div><div role="navigation" class="navbox" aria-labelledby="Time-sharing_operating_systems209" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><div id="Time-sharing_operating_systems209" style="font-size:114%;margin:0 4em"><a href="Time-sharing" title="Time-sharing">Time-sharing</a> <a href="Operating_system" title="Operating system">operating systems</a></div></th></tr><tr><td class="navbox-abovebelow" colspan="2"><div>

<ul><li><a href="Time-sharing_system_evolution" title="Time-sharing system evolution">Time-sharing system evolution</a></li></ul>

</div></td></tr><tr><td colspan="2" class="navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em">

<ul><li><a href="BBN_Time-Sharing_System" title="BBN Time-Sharing System">BBN Time-Sharing System</a></li>

<li><a href="Berkeley_Timesharing_System" title="Berkeley Timesharing System">Berkeley Timesharing System</a></li>

<li><a href="Burroughs_MCP" title="Burroughs MCP">Burroughs MCP</a></li>

<li><a href="CDC_Kronos" title="CDC Kronos">CDC Kronos</a></li>

<li><a href="Compatible_Time-Sharing_System" title="Compatible Time-Sharing System">Compatible Time-Sharing System (CTSS)</a></li>

<li><a href="Cray_Time_Sharing_System" title="Cray Time Sharing System">Cray Time Sharing System (CTSS)</a></li>

<li><a href="Multiple_Console_Time_Sharing_System" title="Multiple Console Time Sharing System">MCTSS</a></li>

<li><a href="MUSIC/SP" title="MUSIC/SP">MUSIC/SP</a></li>

<li><a href="NLTSS" title="NLTSS">NLTSS</a></li>

<li><a href="OpenVMS" title="OpenVMS">OpenVMS</a></li>

<li><a href="ORVYL_and_WYLBUR" title="ORVYL and WYLBUR">ORVYL and WYLBUR</a></li>

<li><a href="TENEX_(operating_system)" title="TENEX (operating system)">TENEX</a></li>

<li><a href="WAITS" title="WAITS">WAITS</a></li></ul>

</div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div>

<ul><li><span class="noviewer" typeof="mw:File"><span title="Category"></span></span> Category</li></ul>

</div></td></tr></tbody></table></div>

<div class="navbox-styles"></div><div role="navigation" class="navbox authority-control" aria-label="Navbox492" style="padding:3px"><table class="nowraplinks hlist navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="row" class="navbox-group" style="width:1%">Authority control databases: National </th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"><ul><li><span class="uid"><a rel="nofollow" class="external text" href="https://catalogue.bnf.fr/ark:/12148/cb119348359">France</a></span></li><li><span class="uid"><a rel="nofollow" class="external text" href="https://data.bnf.fr/ark:/12148/cb119348359">BnF data</a></span></li></ul></div></td></tr></tbody></table></div> </div><div><div class="zim-footer">

This article is issued from <a class="external text" title="Last edited on 2025-07-24" href="https://en.wikipedia.org/wiki/?title=Multics&oldid=1302334769">Wikipedia</a>. The text is available under <a class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en">Creative Commons Attribution-Share Alike 4.0</a> unless otherwise noted. Additional terms may apply for the media files.

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