First, get a copy of the sources from CVS. The CVS sources are kind of in a state of flux right now because we're trying to recode and optimize parts of the original application. To get the sources, follow the instructions on this page.
We use Maven as our build tool. It can generate an Ant build.xml file or Eclipse .classpath and .project files from its project descriptor, project.xml
It is recommended that you use Maven to build development snapshots. We will probably only provide ant build scripts for official releases.
Right now, while Maven 2 doesn't have an official release yet, we're sticking with Maven 1. Also, because Maven 1 can build an ant build.xml file, there will probably be no problems building Virtual Tong-its from source.
You may contribute by doing any of the following:
Patches should be submitted in unified diff format to the project's patch tracker at SourceForge.
You might also want to subscribe to the developer mailing list.