The idea is to have an llvm backend targeting a weird subset of javascript that happens to get optimized really well. As far as I have heard, there are already

The idea is to have an llvm backend targeting a weird subset of javascript that happens to get optimized really well. As far as I have heard, there are already other languages that target emscripten via llvm, and I'm sure there will be more when asm.js gets big. I don't think you'll be stuck with C++.