Eric Lippert (via Ned) is the guy responsible for VBScript and lots of bits of the VBS and JS scripting engines. If you work with them all the time, like I do, then this is already fascinating in bits, and will doubtless get more so.
Randomly connected thought: I wonder how difficult it would be to implement a VBS-to-Python compiler? Has anyone got a YAPPS grammar for VBS lying around? ;)