The engine we use for Alcestis is called ZeroFps and we been coding on it from time to time for fun and to learn new things. It uses OpenGl for graphic as it has to run both on Linux and Windows and each new version of the graphic drivers from ATI/Nvidia gives Dvoid ( one of the other coders on the team ) oceans of joy ;).
Right now I have added a XML interface to Lua, the scripting language we use. The engine uses TinyXml to read XML files and with the glue code I have written we can now open handle the XML files from Lua when we like to. But first, some more thief :D.