This is the source tree or distribution for the rpy2 package.
The distutils mechanism can be used:
python setup.py install
The package is known to compile on Linux, WinXp and MacOSX (provided that developper tools are provided). In the case you find yourself with this source without an idea of what it takes to compile anything on your platform, do consider looking for pre-compiled binaries.
Documentation is available either in the source tree (to be built), or as built HTML online (see the rpy home page on sourceforge).