Instant is a Python module that allows for instant inlining of C and C++ code in Python. It is a small Python module built on top of SWIG and Distutils.
Cinpy is a Python library that allows you to implement functions with C in Python modules. Inlined C code is compiled with tcc (Tiny C Compiler) at runtime. The results are made callable in Python with ctypes library.
Bow (or libbow) is a library of C code useful for writing statistical text analysis, language modeling and information retrieval programs. The current distribution includes the library, as well as front-ends for document classification (rainbow), document
ASL provides peer-reviewed and portable C source libraries. The libraries are intended to be widely useful, leveraging and extending both the C Standard Library and the Boost Libraries.