| > I'd expect to see React up there with Om, Mercury & Elm. Not by default because it's missing laziness and immutability: because just about everything in javascript is mutable, React can't prune out the changeset as the developers could be modifying the application state behind its back in ways unknown (or worse, could be using state which is not under React's control, neither props nor state, but globals and stuff). That is, for safety/correctness reasons the default `shouldComponentUpdate` is `function () { return true; }`. The result is React has to re-render the whole virtual DOM tree (by default) and the only possible gain is when diffing the real and virtual trees. Because Clojurescript and Elm are based on immutable structures they can take the opposite default (and if you're going behind their back and mutating stuff it's your problem). Also, I'm not sure React defers rendering until animationFrame. An optimized React application (or at least one which uses PureRenderMixin[0]) ought have closer performances to the others's (Om is a bunch of abstractions over React after all, so you should be able to have at least as good performances in pure React as you get in Om). [0] http://facebook.github.io/react/docs/pure-render-mixin.html |