UnoCSS (GitHub Repo)
UnoCSS is an instant, on-demand Atomic CSS engine inspired by Windi CSS, Tailwind CSS, and Twind. It is fully customizable, fast, and compact, and it features shortcuts, an Attributify Mode, an inspector, CSS scoping, and more. An online playground is available.
React-Location (GitHub Repo)
React-Location is a router for client-side React applications. It features asynchronous routing, a deeply integrated search params API, route filtering and ranking, and more. A sandbox example is available on the main website.