My latest hack "presence of the wise", a computer game engine with quaternions, numpy matrices and scipy algebra code. It has a balanced tree
which adapts with gradient descent to a minimum for managing the physics
of entities. Entities have a 3D armature with lines, quads and triangles (a la OpenGL). The file 3D/Physics4D.py contains collision code for 3D objects. There is also a small example in the file 3D/NPC/mimic.py, a Mimic (flesh eating chest)
where you can see a 3D entity.

The code is at http://erana.yellowcouch.org/python/ near the bottom of the page.

The license is BSD Revised.

Merry Christmass.

I worked some more on my isometric view game "presence of the wise", it will use tree algorithms for a physics engine and 3D engine. It is 2D for now and has the basics coded for the above. You can find the GPL'd 3 code at http://erana.yellowcouch.org/python

I am going to work some  more on my hidden markov model code, I've put an ID3 tree and the HMM program at http://erana.yellowcouch.org/python

I updated the license from PFL and BSD of my synth-sampler program to GNU's GPL 3, you can find the updated files here :

https://sourceforge.net/projects/pyxiesynth/

pyxiesynth is a program which reads and parses bitstreams from a sound file and then rewrites them back to disk. You can alter the music by shifting and counting bits in an 8-bit packet of audio file (I do not mean the library) then mixing samples from different sources. HTH, enjoy!