CMock is a module/object mocking framework for C projects. It generates dummy modules that conform to the interface specified in a header file. This allows APIs to be proven out and exercised before committing to an underlying implementation.
cfix is a xUnit unit testing framework for C and C++, specialized for Win32 and NT kernel mode. The aim of the framework is to make the development of test suites as easy as possible while fully exploiting the services provided by Windows.