Node.js is one of the worst things to happen to the software industry in recent times, a whole generation of programmers are being taught the worst of all ways of doing concurrency, in a system that doesn't scale either in performance or project size and with one of the languages most plagued by pitfalls ever created.

JavaScript was already painful enough in the browser, why on earth anyone ever thought it was a good idea to use it on the server boggles the mind.

We will be paying the price of this misguided hyped fad for decades to come.

Of all the ways of doing concurrency, callbacks are by far the worst, Twisted was plagued by them and is the main reason why it failed, and that was with a much more sane and reasonable language like Python (stackless Python was a much better alternative and used a model similar to Go's CSP).

And the sad thing is that there are much better alternatives around with much more sound models and environments, Erlang and Go are the two obvious examples, and that is for the highly specialized situations where you have great concurrency needs, for any other problem anything else will be much better than Node.js, even PHP.