An interesting analysis of performances of Asm.js generated by Emscripten versus C native code.
Pros: Asm.js can be really fast on optimized browser (currenltly only Firefox 22).
I’ve made my personnal very small test using The Lua VM, on the Web (higher is better):
- Firefox 22: 430
- IE 10: 133
- Chrome 28: 128
Even if Mozilla have made a great job on its Firefox 22 Asm.js optimizations, Asm.js future depends on its ability to convince either IE or Chrome to join their forces in Asm.js direction.
More details here: Surprise! Mozilla can produce near-native performance on the Web | Ars Technica.