Radare2
UNIX-like reverse engineering framework and command-line toolset
.... Assemble and disassemble a large list of CPUs. Runs on Windows and any other UNIX flavor out there. Analyze and emulate code with ESIL. Native debugger and GDB, WINDBG, QNX, and FRIDA. Navigate ASCII-art control flow graphs. Ability to patch binaries, and modify code or data. Search for patterns, magic headers, and function signatures. Easy to extend and modify. Commandline, C API, script with r2pipe in any language.