A cross-platform framework built in C with multiple language bindings, easing the transition between languages and platforms, while maintaining ABI compatibility.
Monster is a scripting language designed for game development. It is object oriented, type safe, bytecode-compiled, easily merged into existing engines and especially designed to facilitate user-generated scripts. Homepage: http://monsterscript.net
SIEGE is an event-based game engine designed with modularity in mind - one can, for example, swap out the DevIL module for image loading with FreeImage. SIEGE comes with physics, audio, graphics, AI and more, in a cross-platform fashion!
The silc project aims to develop a new programming language called silc, which will be implemented in the D programming language as a frontend for the llvm compiler infrastructure. All the documentation and development is organized at www.silc.ch.