fcd is a LLVM-based native program decompiler. Most of the code is licensed under the GNU GPLv3 license, though some parts, like the executable parsing code, is licensed under a less restrictive scheme.

It implements pattern-independent structuring to provide a goto-free output (when decompilation succeeds).

It uses interpiler to create a code generator from an x86 emulator, making it (usually) very easy to add new instructions to the decompilable set. It uses Capstone for disassembly. Currently, fcd only supports x86_64, though it would be very cool to add new front-ends.

To assist in reverse engineering, fcd can load Python scripts as LLVM passes to clean up custom obfuscation schemes.

fcd is still a work in progress. You can contribute by finding ways to produce a more readable output or by tackling one of the issues that deserves a branch. Additionally, you can help by creating Makefiles or something else that will let fcd build on a non-OS X system (the INSTALL.md file has more information on that topic).