Its kind of like a nicer looking Milkshape by design. I'm using Qt for the GUI and Direct3D for the rendering and it currently has quite a nice feature set for low poly modelling. The legs in the posted image were entirely modelled, rigged and animated from scratch in this software.
It supports all the usual operations, unlimited undo/redo and have recently added a method to do a naive import of a mesh from an X file (no rigging or animations loaded).
The main areas it completely lacks are texture mapping, grouping and subdivision so plenty left to do. The current system for setting vertex weights is also a bit ungainley so have been researching how other modelling software approaches this with a view to improving.
Hope you likey.