Emscripten's role

Emscripten is an LLVM-to-JavaScript compiler, which means it takes LLVM bitcode output of a compiler such as Clang (for C and C++), and converts that to JavaScript. It isn't one specific technology, but rather a combination of technologies that work together to build, compile, and run asm.js. To generate Wasm modules, we'll use the Emscripten SDK (EMSDK)  Manager: