Editing Free Java implementations (section)

==Mid-1990s to 2006==
The first free project to offer substantial parts of Java platform functionality was likely guavac, which began some time before November 1995.<ref>{{cite web
|url=http://www.ccs.neu.edu/research/demeter/course/f96/hw/1/guavac-info
|title=Announcing: guavac 0.2.5, A free compiler for the Java language
|date=1996-09-07
|access-date=2007-06-24
|archive-url=https://web.archive.org/web/20090814181704/http://www.ccs.neu.edu/research/demeter/course/f96/hw/1/guavac-info
|archive-date=2009-08-14
|url-status=dead
}}</ref><ref>{{cite web
|url=http://fresh.t-systems-sfr.com/unix/src/www/guavac-1.2.tar.gz:a/guavac-1.2/compiler/ChangeLog
|title=Changelog of guavac, showing the first release happening in January 1996
|quote=Wed Nov 22 05:43:07 1995 [...] CompilerMain.C, Compiler. C, Compiler.h, lexer.l, parser.y: Initial revision
|access-date=2007-06-24
|archive-url=https://web.archive.org/web/20070928155521/http://fresh.t-systems-sfr.com/unix/src/www/guavac-1.2.tar.gz:a/guavac-1.2/compiler/ChangeLog
|archive-date=2007-09-28
|url-status=dead
}}</ref>

Since then, the [[free software movement]] developed other Java compilers, most notably the [[GNU Compiler for Java]].  Others include the [[Eclipse (software)|Eclipse]] Java Compiler (ECJ), which is maintained by the [[Eclipse Foundation]], and [[Jikes]], which is no longer actively maintained.  Since the [[GNU Compiler Collection]]'s  4.3 release, GCJ (its Java compiler) is using the ECJ [[Parsing|parser]] front-end for parsing Java.<ref>{{cite web
|url=https://gcc.gnu.org/gcc-4.3/changes.html
|title=GCC 4.3 Release Series -- Changes, New Features, and Fixes
|access-date=2007-10-08
}}</ref>

Examples of free [[List of Java virtual machines|runtime environments]] include [[Kaffe]], [[SableVM]] and [[GNU Compiler for Java|gcj]].

[[GNU Classpath]] is the main free software [[Java Class Library|class library]] for Java.  Most free runtimes use GNU Classpath as their class library.

In May 2005, [[Apache Harmony]] was announced, however, the project chose the [[Apache License]], which was at the time incompatible with all existing free Java implementations.

Another event in May 2005 was the announcement that [[OpenOffice.org#Use of Java|OpenOffice.org]] 2.0 would depend on Java features which free software implementations couldn't provide. Following controversy, OpenOffice.org adopted a guideline requiring it to work with free Java implementations.

Notable applications that already worked with free software Java implementations before November 2006 include [[OpenOffice.org]] and [[Vuze]], both of which work when compiled with GCJ.