Before the release of OpenJDK, the JDK was based on a

proprietary license.

Following their promise to release a fully buildable JDK based on almost

completely free and open-source code in the first half of 2007,cite-ref-4[4] Sun

released the complete source code of the Class Library under the GPL on

May 8, 2007, except some limited parts that were licensed by Sun from

third parties who did not want their code to be released under an

open-source license.cite-ref-5[5] Sun's goal was to replace the parts that remain

proprietary and closed source with alternative implementations and make

the Class Library completely free and open source.

Until December 2010, the remaining encumbered part of the JDK was made

available by Sun then Oracle as Binary Plugscite-ref-6[6] which were required to

build the JDK but not necessary to run it. as of May 2007, the only part

of the Class library that remained proprietary and closed-source (4% as

of May 2007 for OpenJDK 7,cite-ref-7[7] and less than 1% as of May 2008 and

OpenJDK 6cite-ref-8[8]cite-ref-9[9]) wascite-ref-10[10] the SNMP implementation.cite-ref-openjdkb10-11-0[11]

Since the first May 2007 release, Sun, with the help of the community,

released as open-source or replaced with open-source alternatives almost

all the encumbered code:

• All the audio engine code, including the software synthesizer, became

open source.cite-ref-openjdkb10-11-1[11]cite-ref-12[12] The closed-source software synthesizer has been

replaced by a new synthesizer developed specifically for OpenJDK called

Gervill,cite-ref-13[13]

• All cryptography classes were released as open-source,cite-ref-14[14]

• The code that scales and rasterizes fonts uses open source

FreeTypecite-ref-15[15]cite-ref-2dproject-16-0[16]cite-ref-17[17]