ParsleyJS - declarative form validation JavaScript library.
Do you want "Node.JS but in PHP" ? :) ReactPHP Event-driven, non-blocking I/O with PHP, looks like trying to do it. Should look closer on it.
ParsleyJS - declarative form validation JavaScript library.
Promise nuggets a github-book by @spion with good explanation and examples for Promises usage. Mostly on Promises alternative to async callbacks approach.
Bluebird - javascript promises library aimed to be almost "as fast as regular callback code" (and 100/10 times faster then Q and when). Worth to try out.
I was waiting for it so long :) Videoconverter.js - FFmpeg converted in JavaScript via Emscripten. It works in client browser, really works. It does not support x264 codec yet, but could be useful to create a video preview on client side etc.
How to install and copy CSS/JS resources via Composer using Composer plugin.