Stefan Lulham created a small script based game engine named
Nabla Nuts, which is based on OpenGL and
irrKlang. It is simple, but interesting, especially because Stefan is developing a game, a tactical RPG with this framework, and
blogging about his experiences while developing it. The script language is
Squirrel by the way, my favourite embeddable language which I am using in
irrEdit as well. Hardly surprising that Squirrel is that nice, it is being developed by Alberto Demichelis, a programmer who was in charge of integrating LUA into FarCry / the CryEngine.