Do threads work? What are the modules that work?
Operating system-level threads basically work. If you enable the thread module then PyPy will get support for GIL based threading. Note that PyPy also fully supports stackless-like microthreads (although both cannot be mixed yet). All pure-python modules should work, unless they rely on ugly cpython implementation details, in which case it’s their fault. There is an increasing number of compatible CPython extensions working, including things like wxPython or PIL. This is an ongoing development effort to bring as many CPython extension modules working as possible.
