http://techcrunch.com/2015/06/17/google-microsoft-mozilla-and-others-team-up-...
Google, Microsoft, Mozilla And Others Team Up To Launch WebAssembly, A New Binary Format For The Web
The new format is meant to allow programmers to compile their code for the browser (currently the focus is on C/C++, with other languages to follow), where it is then executed inside the JavaScript engine.
Over time then, the teams will build more tools (compilers, debuggers, etc.) and add support for more languages (Rust, Go and C#, for example).
https://github.com/WebAssembly/design
JS все, посаны, теперь официально.