Theta is dead. I have stopped work and I don't expect to continue on the code that currently exists. That said, I am considering other routes namely writing a .NET show control library that allows systems to be written at a lower level than the current Theta GUI, but I have no idea when or if I will start working on this.
All this is true, but if you have any interest I would be happy to allow you to have write access so you can continue the project however you see fit. All the source code is in the Sourceforge SVN repository.
-Arthur
Also you can check out the Source Forge project page for THETA.