Node.js is a new-age programming platform based on a software engine at the heart of Google’s Chrome browser.

"Node is the successor to Ruby on Rails, the programming language that made it big when Twitter made it big.
First there was C, which Amazon was written in, then there was Perl that Craigslist was written in. Then there was PHP that Facebook was written in, and then Ruby on Rails that Twitter was written in. With each of these things, they solved a lot of hard problems, but then new problems arrived. Node solves the next set of hard problems, the problems that come with all this real-time stuff.”

http://www.wired.com/wiredenterprise/2012/01/node-dot-js/

http://techcrunch.com/2011/12/21/guide-to-html5-14-predictions-2012/