You can search for communities with https://browse.feddit.de/ .
For Rimworld I found: https://lemmy.world/c/rimworld
PaperlessNgx makes scanned documents searchable. Its great!
Cyperchef might not exactly what you are looking for, but it is selfhosted and has some conversion functions.
Hängeregister.
And I think that’s beautiful.
I would suggest to just start a dummy instance and have a look.