One of the features of Python that makes it so powerful is the ability to take existing libraries, written in C or C++, and make them available as Python extension modules. Such extension modules are often called bindings for the library.
SIP is a tool that makes it very easy to create Python bindings for C and C++ libraries. It was originally developed to create PyQt, the Python bindings for the Qt toolkit, but can be used to create bindings for any C or C++ library. For example, it is also used to create wxPython, the Python bindings for the wxWidget toolkit.
A detailed overview of SIP can be found in the documentation.
SIP is available under the following licenses.