TTRPG Players and DMs, what's in your self hosted toolbox?

Personally I’m running Foundry and have been meaning to spin up Owlbear 1.0 now that it’s self hostable - but I feel like there’s more i could be doing. Is anyone aware of a self hostable character sheet/character builder? I suppose i could go next cloud for storing folders and files but I don’t think anyone would use it...