I've been working on porting the OSX specific libraries in CPython to PyPy and I'm running into issues. The shape of many fundamental data structures used in the CoreFoundation libraries are not available to me. I was hoping to just fudge it by using a ptr to that structure, but it is not working out as I had hoped. Here is a terribly incorrect sample of what I've been hacking on: http://paste.pocoo.org/show/yENK4gE11yRM9i6p46Ra and here is the corresponding osx documentation: http://goo.gl/i6mYD. I was looking at the approach taken for windows, but it is not clear to me where the fundamental structures for windows lie outside of the win32 specific bits in pypy.rpython.lltypesystem.module.ll_os. For the most part they seem to be defined in the modules where they will be used, so it is difficult for me to understand how it all fits together. In general, a higher level description of how to handle data types which you cannot openly declare would be very helpful. Thanks in advance. -- Dan