What things do you self host (or know about) that are fun/interesting/useful to you? I'm thinking of setting up a home server and am looking for things that would be useful or fun for me to run on it. I want to host things that are useful/fun, but not a project itself (I've got enough projects), if that makes sense.

Most of the lists I see online are mostly lists of technical projects like docker, kubernetes, grafana, nginx, etc. I see these as infrastructure rather than the interesting project itself. ETA: the infra is important, but not "interesting" in this context as I deal with infra at my day job.

Examples of the type of service I'm looking at: a media server, photos app (to replace Google Photos), game servers, recipe management, home automation... What other things do you know about that are fun/interesting/useful?

Edit: thank you everyone for your awesome responses!