Article:
http://arstechnica.com/information-technology/2013/05/native-level-performance-on-the-web-a-brief-examination-of-asm-js/
In case anyone is unaware, it's a subset of javascript created by the Firefox team to make code on the browser a lot faster than full javascript, details:
Only problem is, it only runs really fast in Firefox. So does Microsoft have any plans for this technology?