Vue.js - Reactive Components for Modern Web Interfaces
Webix UI - An enterprise JavaScript Library for cross-platform app development with HTML5 JavaScript widgets and easy integration with most popular JavaScript Frameworks.
Polymer - Polymer is a library that uses the latest web technologies to let you create custom HTML elements.
Deku - Functional view library for building UI components as an alternative to React
React - A JavaScript library for building user interfaces
Inferno - An extremely fast React-like javascript library for building modern user interfaces.