I am using Eclipse 3.0 on a windows platform. Here's an example what I did:
I've first created a java project called Xith3d. Then I used the CVS view for checking out the whole Xith3d CVS into existing project (Xith3d). Next I click the project with right mb and select properties. From there I did the following:
1. select tab "Java Build Path".
I remove current build path and add new one by clicking button "Add new folder", now my build path reads "xith3d/src" (right) instead of the default "xith3d" (wrong).
2. select tab "Libraries"
Click button "Add JARs..."
Add the following libraries to your classpath
3. Select tab "Order and export" (not mandatory for Xith examples)
Check every library that you wish to use on a project that depends on Xith3d, e.g. your own Xith3d related test project.
One thing, when you run e.g. Xith3d tests, tell JVM from where to find native libraries. You can do it by selecting run from the menus and then selecting "Arguments" tab and then adding the following (fix pathes) to VM arguments: box:
This makes sure that you use always the same jogl that Xith3d revision is meant to be using. Add lwjgl libraries also there if you need them.
Information for linux users,
Currently Xith does not contain linux native libraries of lwjgl for some reason, I assume you can download them from here: http://sourceforge.net/project/showfiles.php?group_id=58488
Ant is a great tool, but not required (at least not currently) for building Xith3d, Eclipse handles everything nicely.