I looked through the archives and only GHC/Haskell and LLILC have made it: http://blog.llvm.org/2010/05/glasgow-haskell-compiler-and-ll... http://blog.llvm.org/2015/04/llilc-llvm-based-compiler-for-d...

But I think the limitation is on developers willing to write a blog post rather than "serious" development. Excluding "LLVM Weekly" which has since moved to http://llvmweekly.org/, there's been less than 1 post per month, even though LLVM conferences have grown significantly in size.