Glimmer - Fast and light-weight UI components for the web
Deku - Functional view library for building UI components as an alternative to React
Preact.js - Preact is a fast 3kB alternative to React with the same modern API. Components & Virtual DOM.
Svelte - Cybernetically enhanced web apps
Select2 - Select2 offers customizable select box with support for searching, tagging, infinite scrolling, and many other used options.
Inferno - An extremely fast React-like javascript library for building modern user interfaces.