Spine
Lightweight MVC library for building JavaScript applications
Pusher Js
Pusher Javascript library
Mjml
MJML: the only framework that makes responsive-email easy
Alertify.js
JavaScript Alert/Notification System
Simplate
A simple, but powerful, templating engine for JavaScript.
Cram
Simple AMD and CommonJS module bundler.
Nunjucks
A jinja2-inspired templating system for javascript
Sproutcore
JavaScript Application Framework - JS library only
Cellx
Ultra-fast implementation of reactivity for javascript
Hermes.js
Message and Error logger implementation
Hamsters.js
100% Vanilla Javascript Multithreading & Parallel Execution Library
LABjs
Loading And Blocking JavaScript: On-demand parallel loader for JavaScript with execution order dependencies
Kefir
A Reactive Programming library for JavaScript
Script.js
Asyncronous JavaScript loader and dependency manager
Overmind
Overmind - Frictionless state management
Optics
Profunctor implementation of Lenses, Prisms, Traversals, Isos, etc.
Eve.js
A <3kb JavaScript file providing three simple methods to organize code into CSS namespaces which magically restrict code to the current context, allowing for dramatic reductions to code size and development time.