LIEF - Library to Instrument Executable Formats (C++, Python, Rust)
BSD licensed ELF toolchain
A header-only C++ library for accessing files in ELF binary format
RetDec is a retargetable machine-code decompiler based on LLVM
MIPS processor in Java
Japheth's assembler, JWasm
Open Utlity is series of unix utlity just like gnu for linux / windows