What is OpenJDK
From Wikipedia, the free encyclopediahttp://en.wikipedia.org/wiki/OpenJDK
OpenJDK (aka Open Java Development Kit) is a free and open source implementation of the Java programming language.[clarification needed] It is the result of an effort Sun Microsystems began in 2006. The implementation is licensed under the GNU General Public License (GPL) with a linking exception, which exempts components of the Java class library from the GPL licensing terms.
History
Sun's promise and initial release
Sun announced in JavaOne 2006 that Java would become open-source software, and on October 25, 2006, at the Oracle OpenWorld conference, Jonathan Schwartz said that the company intended to announce the open-sourcing of the core Java Platform within 30 to 60 days.
Sun released the Java HotSpot virtual machine and compiler as free software under the GNU General Public License on November 13, 2006, with a promise that the rest of the JDK (which includes the Java Runtime Environment) would be placed under the GPL by March 2007, "except for a few components that Sun does not have the right to publish in source form under the GPL".According to computer scientist and free-software advocate Richard Stallman, this would end the "Java trap", the vendor lock-in that he argues applied to Java and programs written in Java. Software entrepreneur Mark Shuttleworth called the initial press announcement "A real milestone for the free software community".[not in citation given]
Release of the class library
Following their promise to release a Java Development Kit (JDK) based almost completely on free and open source code in the first half of 2007 , Sun released the complete source code of the Java Class Library under the GPL on May 8, 2007, except for some limited parts that some third parties licensed to Sun that rejected the terms of the GPL. Included in the list of encumbered parts were several major components of the Java graphical user interface (GUI). Sun stated that it planned to replace the remaining proprietary components with alternative implementations and to make the class library completely free.
Community improvements
On November 5, 2007, Red Hat announced an agreement with Sun, signing Sun's broad contributor agreement (which covers participation in all Sun-led free and open source software projects by all Red Hat engineers) and Sun's OpenJDK Community TCK License Agreement (which gives the company access to the test suite that determines whether a project based on openJDK complies with the Java SE 6 specification).
Also on November 2007, the Porters Group was created on OpenJDK to aid in efforts to port OpenJDK to different processor architectures and operating systems. The BSD porting projects , led by Kurt Miller and Greg Lewis and the Mac OS X porting project (based on the BSD one) SoyLatte led by Landon Fuller have expressed interest in joining OpenJDK via the Porters Group and as of January 2008 are part of the mailing list discussions. Another project pending formalization on the Porters Group is the Haiku Java Team, led by Bryan Varner.
On December 2007, Sun moved the revision control of OpenJDK from TeamWare to Mercurial, as part of the process of releasing it to open source communities.
OpenJDK has comparatively strict procedures of accepting code contributions: every proposed contribution must be reviewed by two of Sun's engineers and the contributor must have signed the Sun/Oracle Contributor Agreement.(SCA/OCA) Preferably, there should also be a JTreg test demonstrating that the bug has been fixed. Initially, the external patch submission process was and commits to the codebase were only made by Sun engineers, until September 2008. The process has improved and, as of 2010, simple patches and backports from OpenJDK7 to OpenJDK6 can take place within hours rather than days.
On 2010-10-11, IBM and Oracle announced that both companies will collaborate to further develop OpenJDK.
On 2010-11-12, Apple and Oracle announced the OpenJDK project for Mac OS X.
Status
Supported JDK versions
OpenJDK was initially based only on the JDK 7.0 version of the Java platform.
Since February 15, 2008, there are two separate OpenJDK projects:
[*]The main OpenJDK project, which is based on the JDK 7.0 version of the Java platform,
[*]The JDK 6 project, which provides an Open-source version of Java 6.0.
Compiler and Virtual Machine
Sun's Java compiler, javac, and HotSpot (the virtual machine), are now under a GPL license.
Class library
<div class="rellink boilerplate seealso">See also: Java Class Library
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