Compiling Rust to Wasm manually with the LLVM wasm-backend (without Emscripten)
EDIT November 2017: recently the target
wasm32-unknown-unknown was added to
rustc which uses the LLVM WASM backend and works without Emscripten. This is now the recommended way of generating WASM code from Rust (as it is much easier). Thus, this gist document is pretty much useless now. A great resource on getting started with WASM and Rust is hellorust.com: Setup and Minimal Example.