capstone-engine.org

Capstone is a disassembly framework that offers a lightweight, intuitive API for binary analysis and reversing in the security community. It supports multiple hardware architectures and provides semantic analysis of disassembled instructions. Capstone is implemented in C with bindings available for multiple programming languages, natively supported on various platforms, and thread-safe. It is suitable for malware analysis and has special support for embedding into firmware or OS kernel. Capstone is open-source under the BSD license and its technical details are available in Blackhat USA 2014 slides. Additional information is available on their website.