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.

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.

Currently, the code has dependencies on __builtin functions that should be supported by both modern Clang and GCC (but not MSVC).

fcd uses a relatively old version of Daniel Berlin's MemorySSA utility, found in his GVN rewrite branch at dberlin/llvm-gvn-rewrite. The version used is git commit e80e9fd27680ab3566b06d9882fcbeb83fa53688. This could use some updating.