Not all the horror was Windows, mind: Linux's interface to executables is barely documented and extremely fragile, involving passing a key-value table full of magic parameters on the stack after the argument and environment tables. (The LBW instruction patching code is here. I'm actually now kind of scared at how much working hackery LBW ended up containing: it'd dynamically patch the binary after trapping out at instructions manipulating things that Windows wouldn't allow access to.

Yeah, it ground to a halt due to fundamental differences in the way Linux and Windows binaries work.