You should get the source code from its most current Subversion version at http://codespeak.net/svn/psyco/dist/. (The command is ``svn co http://codespeak.net/svn/psyco/dist/ psyco-dist``)
People unfamiliar with Subversion or whose Subversion access is firewalled can use a web grabber (e.g. ``wget -r http://codespeak.net/svn/psyco/dist/ -I /svn/psyco/dist``).
Note that the Subversion tree is considered the latest official release. It evolves slowly and it is more stable than the packaged version.
To install from the source, run the top-level installation script setup.py:
python setup.py install
As usual, other commands are available, e.g.
python setup.py build_ext -i
will compile the C source and put the result directly into the py-support/ subdirectory (no administrator priviledge is required). After this step, the py-support/ directory is a complete package (exactly as found in the binary distributions) that you can rename to psyco and copy around.