Alertify.js
JavaScript Alert/Notification System
Inferno
An extremely fast, React-like JavaScript library for building modern user interfaces
jTypes
jTypes is the most comprehensive and robust JavaScript library for overcoming differential inheritance with prototype-based objects. Its lightweight yet powerful design provides web programmers on any platform or browser the ability to emulate classical inheritance where objects are defined by classes.
Simplate
A simple, but powerful, templating engine for JavaScript.
Spine
Lightweight MVC library for building JavaScript applications
Qooxdoo
A Universal JavaScript Framework
Mjml
MJML: the only framework that makes responsive-email easy
JavascriptMVC
Develop with direction! With CanJS, jQuery++, FuncUnit, Steal, DocumentJS.
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
Nunjucks
A jinja2-inspired templating system for javascript
Script.js
Asyncronous JavaScript loader and dependency manager
Overmind
Overmind - Frictionless state management
Webix
Stable releases of Webix UI - JavaScript library for building mobile and desktop web apps
Optics
Profunctor implementation of Lenses, Prisms, Traversals, Isos, etc.