Sandstorm does this, although we are badly in need of funding, contributors, and all the things needed to meaningfully run an open source project. Our updates are generally evergreen but we are currently blocked on offering that while we establish a new community-run infrastructure and development process.

The problem is you do need to reinvent everything to do this right, and reinventing everything is hard and a bit of a slog. Some problems are also just... still hard, there's no secure and good way to help someone open a port on their home router.