Roel Jordans has resurrected the C back-end to LLVM, which was dropped following the LLVM 3.1 release. The C back-end is for generating C code out of LLVM bit-code. While an interesting back-end, the previous version wasn't actively maintained and not in the best shape.\
Roel cleaned up this existing back-end, which he is doing as part of research work, and has already brought it up to a working state.
For his new CBackend he's looking at new features like a type legalization pass, simplification of the output, and other features. He hopes that the simplified C output will produce more friendly and portable output.
Roel Jordans shared this work in a new thread on the llvmdev mailing list where he is seeking comments about desired features and capabilities of the new LLVM CBackend.