Experimental ThinScript language backs WebAssembly
WebAssembly is being developed under a partnership that involves major browser vendors Apple, Google, Microsoft, and Mozilla. It features a portable code format intended to run at native speeds in browsers, where it is being previewed.
With ThinScript, developers gain a language that accommodates WebAssembly right from the start. But documentation for ThinScript emphasizes that WebAssembly is still "a volatile work in progress," with the binary format set to be changed before its final release. "Debugging support for WebAssembly is non-existent in current implementations. You get the idea."
A demo of the ThinScript compiler is available.