Selectize is the hybrid of a textbox and <select> box. It's jQuery based and it has autocomplete and native-feeling keyboard navigation; useful for tagging, contact lists, etc.
jQuery Validation Plugin
A package manager for the web, created at Twitter
Handlebars provides the power necessary to let you build semantic templates effectively with no frustration. An extension to the Mustache templating language created by Chris Wanstrath.
The official jQuery user interface library.
Medium.com WYSIWYG editor clone.
SVGO is a Nodejs-based tool for optimizing SVG vector graphics files.
The de-facto solution to flexible routing with nested views
browser-side require() the node.js way
Realtime MVC Framework for Node.js
A kickass library to manage your poppers