JDK 6 Project
The primary goal of this project is to produce an open-source implementation of the Java SE 6 Platform. Various binaries derived from OpenJDK 6 sources have passed the Java SE 6 Test Compatibility Kit (TCK) suite, including packages for Fedora 9 and Ubuntu 9.04.
Genealogy
The OpenJDK 6 code base is distinct from the code base for JDK 7 and the 6 update train. As shown in the diagram below, the original JDK 6 code base begat two lines of heirs: JDK 7 and the sequence of 6 update releases. The decision to open source the JDK code base came late in the life cycle of the development of JDK 6 so a build of JDK 7 was the first to be published as open source. By the time JDK 7 was published as OpenJDK 7, the first post-GA update to JDK 6, 6u1, had already shipped. Work continued in both the OpenJDK 7 and 6 update trains. However, an open source implementation of the Java SE 6 specification was needed as well. After considering the alternatives, OpenJDK 7 build 20 was chosen as the basis of a backward branch to create OpenJDK 6 by removing from the OpenJDK 7 sources changes inappropriate for a Java SE 6 implementation. Since then, all three trains, 6 update, OpenJDK 7, and OpenJDK 6, have continued evolving, with certain fixes being applied to or ported between the releases. Security fixes are applied to all release trains.
