I believe it's open, and not patented (or I'm wrong?), an attempt to bring LLVM IR (quite standardized) to browser side. It's redundant (competes with asm.js, which is the same kind of "non-standard nonsense" with a WIP spec) with it's own pros and cons, but that's about it.
Every browser vendor experiments with new ideas, only because of this we're getting nice things as the results.