WebAssembly, the much-anticipated portable code format positioned to boost web performance, proceeded to a release candidate stage Monday. The technology is expected to be shipped on-by-default in browsers after a specification release next year.
"Barring major design changes arising from community feedback, the WebAssembly Community Group plans to produce an official specification in Q1 2017, at which point browsers will be encouraged to ship WebAssembly on-by-default," the V8 group said. "From that point forward, the binary format will be reset to version 1 and WebAssembly will be version-less, feature-tested, and backwards-compatible." But Wagner cautioned, "Things will change right up until the standard is marked done and WebAssembly is enabled in browsers -- and then it's back to don't break the Web as usual."
Since WebAssembly is still behind a flag in Chrome (chrome://flags/#enable-webassembly), it is not yet recommended for production use. "However, the Browser Preview period marks a time during which we are actively collecting feedback on the design and implementation of the spec. Developers are encouraged to test out compiling and porting applications and running them in the browser," the V8 group said. V8 is optimizing WebAssembly in the TurboFan compiler, and an alternative asm.js pipeline converting asm.js to WebAssembly so that existing asm.js sites can benefit from WebAssembly ahead-of-time compilation is nearing completion.