I’m currently implementing a project built around the MetaPost library MPlib. I managed to build MPlib as a Windows .lib (library) file without “too much” difficulty… In order to understand the workings of the powerful, but complex, MPlib library I found it was very helpful to read parts of Hobby’s original code – mainly in relation to generating output from the low-level MPlib/MetaPost edge structures. I also benefitted enormously from reading the C code of the Lua binding so a huge thank you to Taco Hoekwater for his utterly brilliant work on the MPlib/lmplib source code.
I tracked down the MetaPost 0.64 source code (the .web code) and ran TIE and WEAVE to generate the TeX documentation. After a few tiny fixes (for fonts I don’t have) I produced a PDF file which I thought others might find useful. You can download it here. The MPlib API documentation (again by Taco) was also very helpful – documentation for version 1.800 of the MPlib API is available here.