A reimplementation of the invidious api based on a youtube-dl backend, together with a js-light frontend. I'm working on something similar, but leveraging youtube-dl to actually be platform-agnostic.
No Invidious official release since 2019 and it had huge memory leak issues that was unresolved for months last time I checked. Public instances were constantly restarting docker instances to work around it.
The invidious repo is very active though, does an official release actually matter?