Red Hat has joined Sun Microsystems' open-source Java Standard Edition (SE) project, OpenJDK, and will coordinate its own Linux Java development efforts with the project.

Red Hat has signed the OpenJDK contributor agreement and will now align its IcedTea project, which was its own implementation of some parts of the Java SE JDK, with OpenSDK, said Shaun Connolly, vice president of product management for JBoss.

IcedTea brought together the Fedora project with key Java technologies, and currently provides open-source alternatives for the few remaining proprietary sections in the OpenJDK project, he said. Fedora is a Red-Hat sponsored Linux project.

Red Hat also has licensed the OpenJDK Community Test Compatibility Kit (TCK), which allows it to implement OpenJDK and test its compatibility with the implementation the project itself develops, he said. The Java SE JDK, the basis for OpenJDK, includes the Java Runtime Environment (JRE) as well as tools for developing Java applets and applications; it is the software that is the basis for desktop Java applications.

Red Hat eventually will create a compatible OpenJDK implementation for its Enterprise Linux distribution. It also will also use OpenJDK to create a runtime for its JBoss Enterprise Middleware that is optimised for Linux, according to the company.

Prior to its purchase of JBoss and its Java-based middleware last April, Red Hat and Sun were competitors in the OS market, and Red Hat wasn't very active in the Java community. However, now that the company is pushing its open-source strategy beyond Linux and using JBoss as its first step to get there, Java is becoming more integral to its overall product plan.

When it was an independent open-source company, JBoss was an active member of the Java Community Process (JCP), the formal group that oversees Java. Earlier this month, Red Hat's middleware division was re-elected to a position on the Executive Committee for the SE/Enterprise Edition (EE) project within the JCP, a position that lasts three years and is the one JBoss occupied.

Red Hat ships JBoss middleware with its Red Hat Enterprise Linux, and includes three different implementations of the Java SE JDK from IBM, Sun and BEA Systems, Connolly said. The company will continue that strategy in the near term, but eventually will include an open-source version of the JDK that it can make changes to dynamically for customers without having to worry about when third-party companies will update their software, he said.