Dont forget my GLXTreem . My host is kindof bugged atm so the page is down, but the downloads is avaiable at:

http://www.glxtreem.net/downloads/

and some screens can be found at:

http://www.glxtreem.net/screens/

Some of the features is Geomippmapped terrain, GLSL support, MS3d, 3ds and obj loaders, with plugin support. Xml based quite powerfull gui editor, scriptable particle system, and Q3BSP rendering with patches meshes, Physics engine via Trueaxis.

But its more in the line of glsceene, a set of helper components for writing your own engine then a fullfledged engine.