Hi Charlie, We distribute the Chimera headers and Python headers but it is a separate download. They can be obtained from the Chimera Programmer's Guide page. http://www.cgl.ucsf.edu/chimera/docs/ProgrammersGuide/index.html The current headers are for Chimera version 1.2180 (and are identical for 1.2181). You should be able to compile matplotlib and other Python modules using the Chimera Python and Chimera Python headers for use within Chimera. For the soon to be released Chimera production version (probably 1.2182) we will put the Chimera code and headers on the source code download page: http://www.cgl.ucsf.edu/chimera/sourcecode.html Currently the headers are not on that page and are hard to find in the Programmer's Guide. Tom