[ghelmer]

I have been unpleasantly surprised when I expect Posix semantics from Windows. Think about parent PIDs. You can't assume a process's parent PID is actually still the parent. Think about file open semantics. Try to open to a file when any other process has the file open with no sharing allowed. Think about file delete. (Really, try to delete a file reliably in Windows.) Think about string encoding and code pages. (Well, this is out of bounds for Posix, but closely related to expected filename semantics.)