radare2 aims to create a complete, portable, multi-architecture, Unix-like toolchain for reverse engineering. It is composed of a hexadecimal editor (radare) with a wrapped I/O layer supporting multiple backends for local/remote files, debugger (OS X, BSD, Linux, W32), stream analyzer, assembler/disassembler (rasm) for x86, ARM, PPC, m68k, Java, MSIL, and SPARC, code analysis modules, and scripting facilities. It also has a bindiffer named radiff, base converter (rax), a shellcode development helper (rasc), a binary information extractor supporting PE, Mach0, ELF, class, etc. named rabin, and a block-based hash utility called rahash. Radare was rewritten as radare2, and the old version is only maintained for bugfixes.
Capstone is a disassembly framework with the target of becoming the ultimate disasm engine for binary analysis and reversing in the security community. Running on Windows, Mac OS X, Linux, FreeBSD, OpenBSD, and Solaris, it can disassemble ARM, ARM64 (ARMv8), MIPS, PPC, and x86 architectures. Capstone provides rich details about disassembled instructions along with useful semantic information.