For the old (and somewhat outdated) documentation, please see the HTML file: doc/index.html. For the new, work-in-progress, but up-to-date documentation, see http://pytsai.readthedocs.org/en/latest/. This is an actualized version of pyTsai (for python 3.3 and Blender 2.65) I found the original (for python 2.4, 2.5 and 2.6 and Blender 2.4) at: http://farmerjoe.info/?p=7 To install the Tsai extension for Blender (2.65) (at leat under Windows, which has a separate Python environment), just copy the contents of the PyTsai-1.0.win-amd64-python3.3.zip into the [...]\Blender Foundation\Blender\2.65\scripts\modules (NOT the whole folder tree, only the files and the __pycache__ folder).