My take on this: - If you're building a web app (perhaps a single page web app), it might be useful that you can share client side code and server side code.

My take on this: - If you're building a web app (perhaps a single page web app), it might be useful that you can share client side code and server side code. Take input validation as an example -- you can use the same `validateEmailAddress` function on the server and on the client -- guaranteed to be consistent. - Javascript is a fascinating language. - Maybe others can contribute some performance numbers? My impression is that V8 is very fast -- can JS outperform other scripting languages? - The whole Node.js approach to concurrency is very different than using threads -- it's fascinating, as well.