Coming back to original question...
alive that's good i guess that means we can use it but is it still being developed?... that was original question...Dave was main horse behind it and now when he left even his own creation (magiscosm) question is - is there anybody still thinking about added new features - or is it going to stay as is it from now on .....
Yes, Xith3D is still being developed. Last few months I made many contributions (primarily bug/compatibility fixes) to Xith3D and I plan to do this in future.
There are some things I see as main goals for nearest future:
1. Reduce amount of garbage produced by rendering engine.
2. Add support for LWJGL-based renderer.
3. Add support for more extensions exposed by latest hardware (point sprites, texture rectangle, occlusion testing, OpenGL 1.5 features, etc.).
4. Stereo rendering (there are already some successful tests with Red-Blue stereoglyphs, but I am thinking about other stereo rendering techniques).
5. Additional culling mechanisms.
In parallel, I am thinking about exposing to the developers internal multipass rendering mechanism in order to support render-to-texture and other specific multipass rendering techniques.
This is a short list, and of course there are a lot of smaller topics.