The GNU Classpath Extensions project builds free versions of Sun's Java extension libraries, the packages in the javax namespace. It is a companion project of the GNU Classpath project.

ClasspathX produces vendor neutral Java code: it should work with any VM. However, we particularly want the code to work with free VMs such as gij and kaffe.

We need help

Attempting to build free versions of ALL of Sun's Java extensions is a big job and we need your help to get everything done. If you are a Java programmer and you want to work on building free Java extensions then get in touch with either Chris Burdess or Arnaud Vandyck who will be happy to give you something interesting to do!

If you want to write code you must assure us that you have not seen the source code for the API you want to work on. If you have seen Sun's source code we can't accept your contributions as they would put the entire project at risk from legal action.

If you can't contribute code, either because you don't think you're qualified or you've seen Sun's source code, you can still be of tremendous help to us. We need testers and people to write documentation as well as hackers!

Keep in touch

To know what's going on with the project you can subscribe to our very low volume announcements mailing list by sending a mail with the subject line:

to the address

If you are interested in becomming a developer it may be useful to track one of the development mailing lists. There is a mailing list for each major project. Check the individual project pages (or the savannah system) for more info. There is a general discussion list for classpathx developers which you can join by sending a mail with the subject:

to the address

Packages currently under development


Releases for each separate part of the ClasspathX project are maintained, well, seperately. Check each project's page for details.

We do not plan to offer a full ClasspathX download, but if you'd be interested in having one you should maybe let us know.


Development for ClasspathX occurs on the savannah free software collaboration system. You can view our code in CVS from there. If you want to help us you will need to become a savannah user.


Andrew Selkirk started this project as an open source effort in 2000. He did all of the hard work creating the free versions of the various javax APIs listed above. He was also gracious enough to hand on the work to the GNU project when he found himself too busy to continue. Andrew stays in touch with the project and we'd like to give a a very big thank you to Andrew for his effort, vision and magnanimity.

David Brownell contributed the JAXP, SAX and DOM code. With another hat, he's a maintainer for the SAX2 interfaces. Thanks for the help David!

Chris Burdess (aka dog) wrote the JavaMail and JAF implementations and providers.

Paul Siegmann, who wrote the original free version of the servlet API and trailblazed the legalities of the GNU project clean rooming javax source code. Paul spent many days typing in code worked out from javadoc. He deserves a lot of thanks, so...
Lots of thanks Paul!

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Updated: $Date: 2006/11/23 09:22:28 $ $Author: ramprasadb $