Win32 Disassembler. Produces annotated dissassembly of .EXE file and .DLLs. The dissassembler knows about 100s of calls to well known Win32 APIs and documents the assembly for you so that one can understand what the assembly code is trying to do. Very handy when one is trying to understand what a piece of binary code is doing when

one does not have access to its source code, aka reverse engineering.