Preact.js - Preact is a fast 3kB alternative to React with the same modern API. Components & Virtual DOM.
digiKam - Professional Photo Management with the Power of Open Source
Inferno - An extremely fast React-like javascript library for building modern user interfaces.
XnView MP - XnView is a free software that allows you to view, resize and edit your images. It supports more than 500 different formats!
Glimmer - Fast and light-weight UI components for the web
FastStone Image Viewer - FastStone Image Viewer is a fast, stable, user-friendly image browser, converter and editor.