It’s not too bad (build.xml).

It has targets to do the two main things you need:

  • create (and delete) the pointer file in your Firefox profile/extension directory
  • create xpi files for releases

and it gets some of the information it needs from the project’s install.rdf.

You have to edit the build.xml project name and the path to your Firefox profile. Everything else comes from install.rdf. I used to get annoyed about manually updating version numbers and stuff in multiple places, and having different ant scripts for my projects so now it just works.