With only a few concepts (views, actions, effects, and subscriptions) Hyperapp is easy to learn and get going. Its declarative API is easy to read and fun to write and build purely functional, feature-rich, browser-based apps using idiomatic JavaScript. Hyperapp is an ultra-lightweight Virtual DOM, highly-optimized diff algorithm, and state management library obsessed with minimalism.
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.
React - A JavaScript library for building user interfaces
Polymer - Polymer is a library that uses the latest web technologies to let you create custom HTML elements.
Svelte - Cybernetically enhanced web apps
Jumpsuit - A minimal React and Redux framework