The flagship instance is: https://ln.ht
The source code is hosted here: https://sr.ht/~mlb/linkhut/
The documentation: https://docs.linkhut.org/introduction.html
Two things that I think are very important in a bookmarking app (and why I‘ve been working on making one of my own on and off for a while): open source and offering an API for other tools to build upon. The current API on linkhut aims to be bug for bug compatible with pinboard while being more OAuth-y.
I’m still working on a snapshotting feature similar to pinboard’s, once that’s ready I think I’ll call 1.0 complete. Perhaps I’ll do a Show HN then.