Just like Node is Twisted in Python or EventMachine in Ruby.

So it's not exactly a new technique, "just" a new technology bringing a lot of fresh air. :)

I don't think anything like Mojolicious exists in other programming languages. It's a mix of a lot of concepts, while still being standalone, while still providing everything you need and while still being fast. I think everyone that isn't forced to use something else should give it a try (maybe even reimplement something in a different language), because I never saw a quicker way to get where you want.