Semantic UI - a toolkit for web UI with semantic layout. Actually looks more semantic and clear (in terms of HTML code) than Bootstrap.
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.
Semantic UI - a toolkit for web UI with semantic layout. Actually looks more semantic and clear (in terms of HTML code) than Bootstrap.
Hand-picked registry of Node.js frameworks. Makes you a suggestion for mature framework to start with a little easier (according to specific of your needs).
PuPHPet - simple GUI to set up virtual machines Vagrant + Puppet for Web development.
Mobile-Detect - a lightweight PHP class for detecting mobile devices. Works like $detect->isMobile()
etc., very handy for choosing a frontend rendering strategy based on this info.
Official Elasticsearch client library for Node.js and the browser.