The main components of OpenJDK are:

• The HotSpot Java Virtual Machine (JVM)
• The Java Class Library (JCL)
• The Java compiler, javac

Initially, OpenJDK needed to be built using a proprietary JDK. However, the IcedTea project allowed us to build OpenJDK using the GNU classpath, the GNU Compiler for Java (GCJ), and bootstrap a JDK to build OpenJDK. It also complements OpenJDK with some missing components available on Java SE like a web browser plugin and web start implementations.

Yocto can build OpenJDK using the meta-java layer, which includes recipes for cross-compiling OpenJDK using IcedTea. Development discussions can be followed and contributed to by visiting the development mailing list at http://lists.openembedded.org/mailman/listinfo/openembedded-devel.

The meta-java layer also includes recipes for a wide variety of Java libraries and VMs, as well as tools for application development like ant and fastjar.