Free Disassemblers and Decompilers
RECReverse Engineering Compiler
REC is a portable reverse engineering compiler, or decompiler. It reads an executable file, and attempts to produce a C-like representation of the code and data used to build the executable file.
A disassembler for Win32 PE files
Symbolic disassembler for Win32.
Win32 disassembler and resource extractor.
A cross dissassembler that dissassembles 680xx binary code using a PC