If you would like to work seriously on a piece of existing NetBeans code:

  1. Make sure you are subscribed to (and read!) the relevant mailing lists so that you know what is going on in that area of development. It is really necessary to subscribe to broken builds notification mailing list.
  2. Make sure you have looked through the existing source code and understand what it is doing and how. If something is poorly documented, confusing, or you just can't grasp what is going on, ask on the associated mailing list for a summary. Probably the original developer should write better Javadoc or other documentation to explain it anyway.
  3. Make sure you have a loginon the site. Anyone can make one for him or herself (but without any special permissions). You will need one for using IssueZilla, CVS, and so on.
  4. Submit some patchesso that it is clear you know what you are doing.
  5. Ask the maintainer to be given checkin permission on an area of the codebase, and explain what sorts of things you are interested in doing with it. You will need to communicate frequently with person or people who already maintain that area of code, so make sure there is an agreement on what you should be working on.
  6. Also mention in writing that you understand that your work is on SPL (Sun Public License)code and that you agree that all changes you make are things you write yourself and that they can be incorporated under the SPL.
  7. You must have filled in a Contributor Agreement - see the CA Policypage for more info. No code can be committed until a CA is completed.
  8. While logged into the site, request the Developer role on the modules you are interested in - from the module's home page, click the "Member's" link, and you should see a "Join this module" link. This sends a request to the module owner(s), which can be approved or not. The module owner ought to mention on nbdev new people he or she is approving as developers with a summary of what they are working on, and initially take responsibility for making sure they know what to do.
  9. If approved, you can begin working. Make sure you understand which CVS branch you are supposed to be working on! Also make sure you read and understand the Commit Rules.
  10. Make modifications and enhancements and talk about them on the associated mailing lists.
  11. If you need checkin permission for the whole repository, you can request a "grandfather" role, which has write permissions everywhere. If you think you need to do this, please ask on nbdev, and explain why you need it. Give people at least a few days to react to your request before asking that it be granted. This role should not be required often, but is helpful for major refactorings etc.

Source: NetBeans FAQ