The most advanced responsive front-end framework in the world. Quickly create prototypes and production code for sites and apps that work on any kind of device.
Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jade, coffee, css, less, ... and your custom stuff.
A React-based UI toolkit for the web
Async utilities for node and the browser
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.
Give your JS App some Backbone with Models, Views, Collections, and Events
React Native for Web
Jade - robust, elegant, feature rich template engine for nodejs
Observable data. Reactive functions. Simple code.
Simple, scalable state management.
Realtime MVC Framework for Node.js
Ajax with less suck - (and node.js HTTP client to match)