"With this, developers can start shipping WebAssembly code. For earlier versions of browsers, developers can send down an asm.js version of the code. Because asm.js is a subset of JavaScript, any JS engine can run it. With Emscripten, you can compile the same app to both WebAssembly and asm.js.Even in the initial release, WebAssembly will be fast. But it should get even faster in the future, through a combination of fixes and new features."
"With this, developers can start shipping WebAssembly code. For earlier versions of browsers, developers can send down an asm.js version of the code. Because asm.js is a subset of JavaScript, any JS engine can run it. With Emscripten, you can compile the same app to both WebAssembly and asm.js.Even in the initial release, WebAssembly will be fast. But it should get even faster in the future, through a combination of fixes and new features."