Use.js
An AMD/RequireJS plugin for consuming incompatible JavaScript files.
PreloadJS
PreloadJS makes preloading assets & getting aggregate progress events easier in JavaScript. It uses XHR2 when available, and falls back to tag-based loading when not.
Knockout
Knockout makes it easier to create rich, responsive UIs with JavaScript
Pilot
Pilot — multifunction JavaScript router.
Twitterlib
Twitter JavaScript API library
Jade
Jade - robust, elegant, feature rich template engine for nodejs
Delorean
An Agnostic, Complete Flux Architecture Framework
Mask Js
Zen Coding | Markup | Template | HMVC
Connective
agent-based reactive programming library for typescript
Dozerjs
Foundational Framework for NodeJS Web Services
Oc Lazy Load
Load modules on demand (lazy load) in AngularJS
Flagsmith Frontend
Web App and Mobile App for Flagsmith
Nunjucks
A jinja2-inspired templating system for javascript
JayData
JayData is a unified data access library for JavaScript to CRUD data from different sources like WebSQL/SQLite, IndexedDB, MongoDb, ASP.NET WebAPI, OData, HTML5 localStorage, Facebook or YQL. The library can be integrated with KendoUI, Knockout.js, Handlebars.js or Sencha Touch 2 and can be used on Node.js as well.
Fluxxor
Flux architecture tools for React
Backbone Nested
A plugin to make Backbone.js keep track of nested attributes.
Autolink Js
Tiny little tool to find URLs in a string of text and hyperlink them