Since the previous engine (up to release 0.5b - SVN 160) was very complex and quite unstable, a new attempt is under development.
This new attempt, code-named "G-Engine", is not re-implementation of the engine, but rather a clean-up and reform of the previous engine. It wraps all the previous messy code under namespaces and objects and introduces a new object-oriented approach.
Also, the G-Engine provides a new, simpler extension support, that allows users and third parties to create their own extensions to the game.
You should also keep in mind that because of this, the support to the previous engine versions cannot be provided any longer.
Finally, since this is a fresh start, we would appreciate your support, either by contributing to the development (with ideas or by joining the development team), or by donating to the project.