Preact.js - Preact is a fast 3kB alternative to React with the same modern API. Components & Virtual DOM.
Dropzone - If you want your file uploads to work even without JavaScript, you can include an element with the class fallback that dropzone will remove if the browser is supported.
Inferno - An extremely fast React-like javascript library for building modern user interfaces.
Dropover - Mac app for easier drag & drop
Glimmer - Fast and light-weight UI components for the web
Unclutter - Unclutter is an app that is designed to help Mac users bring order to their desktop. Among other features, this powerful piece of software provides quick access to a user's notepad and clipboard.