WinAVR (tm) is a suite of executable, open source software development tools for the Atmel AVR series of RISC microprocessors hosted on the Windows platform. Includes the GNU GCC compiler for C and C++.
diStorm is a binary stream disassembler for AMD64 and 80x86-16,32 bits. It disassembles FPU,MMX,SSE,SSE2,SSE3,SSE4,VMX and 3DNow!(w/exts) and new x86-64 instruction sets. diStorm was written to decode quickly every instruction as accurately as possible.
Adebug/Assemble is a pair of Debugger/Assembler for the MC68Xxx family running on Atari and Amiga computers. Years ago commercial product, now GPL.
The Developer Resources Sega Genesis and Super Nintendo development tools and libraries In 1992 I (Kevin Seghetti) and some friends had a company (Developer Resources) which provided development tools for the Sega Genesis and the Super Nintendo console
playstation (psx) development tools: includes disassembler, code profiler, and cd mastering tools (split off from the World Foundry GDK).