PyPy has become a popular alternative to the standard Python implementation. More importantly, it is now being used by many companies (small and large) in their production environments to boost performance and scalability. How does PyPy differ from normal CPython? While the latter is a traditional interpreter, the former is a full-fledged virtual machine. It maintains a just-in-time compiler backend for runtime optimization on most relevant architectures.
Getting Cythonized modules to run on PyPy is dependent on their cpyext emulation layer. This isn't quite complete and has many inconsistencies. But, if you are brave and up to trying it out, it's going to get better and better with each release.