not sure if react-specific showcases are considered OK, but i published this yesterday, could turn into a nice collection of useful helpers: https://github.com/react-spring/drei
if you click the sandbox links you can see it working. these are mostly abstractions for boilerplate-heavy primitives. saw myself repeating set-up code for things like controls, wiring up update loops, etc, so i thought: why not make it re-usable. all these components are self-managed and will clean up on unmount.