multi-platform cross assembler for 6502/6510/65816 cpu
The Open On-Chip Debugger
RetDec is a retargetable machine-code decompiler based on LLVM
Binutils port for the Sharp SM83 (GameBoy CPU)
M6811 Code-Seeking Disassembler
A machine code manipulation library for Intel 64 and IA-32.
Japheth's assembler, JWasm
A low-power ISA design and simulator for a 2010 IEEE competition
A disassembler and a simulator for the MSP430 CPU
Emulator and assembler