The Apache Software Foundation is considering developing a new open-source implementation of Java 2 Standard Edition (J2SE) 5, to be codenamed Harmony and issued under Apache Licence 2.0.

If the project goes ahead it may provide firms with a better open-source J2SE 5 system, compared with those from Kaffe and Classpath and others, and may be an attractive alternative to commercial J2SE implementations.

Before Sun released version 5.0 of J2SE, its licensing restrictions prevented anyone from making an open-source implementation.

The Apache licence is well suited to business use because it allows third parties to modify the Apache code and retain the copyright to those modifications.

Geir Magnusson, who proposed the project to the ASF earlier this month, said managing intellectual property rights was a vital consideration. In particular, developers working on the project would be asked to declare any previous work on non-open-source class library or Java virtual machine source code so that those individuals could be prevented from developing related parts of the Harmony software. This precaution is intended to prevent accidental violations of third-party copyright that could occur where a programmer works on two very similar projects.

Observers said such a project would be a massive undertaking that would take several years to complete. One poster to online discussion boards said: "Sadly the reality is that no Java [implementation] is even remotely as reliable or complete as Sun's for the desktop let alone anywhere else. Major work had to be done to the GNU Compiler for the Java just to make Open Office 2.0 run, which hardly speaks for its maturity. And other implementations such as Kaffe are missing critical security functionality such as byte code verification.

Personally, I'd love to see a free and open-source Java, but it's taken years to get this far and its still not there yet."

Others were more positive and welcomed the move, noting that some of the developers who had worked on alternative projects, including Kaffe and Classpath, were very likely to contribute to the Harmony project.

Another online poster said: "This appears to be a consolidation project. We have several contenders for open-source JVMs [Java virtual machines], but most of them lack in some way or the other compared to the Sun and IBM JVMs. Having one up to-date one instead of five not-quite-there-yet ones is a step forward."