Thinking of hosting one for myself and was wondering what the downsides of each are. Do they all interact fine with each other? Can I log into mastadon apps with misskey/pleroma accounts? Is it like lemmy where the app specifically needs to support mbin (interstellar) to use that account?
Which one requires the least resources? I'm on ios so I'll likely gravitate towards whichever one works best with ios apps. I do see that sora sns seems to support all of them + bluesky.
I would rather suggest the Akkoma (=pleroma) and Sharkey (=Misskey) forks for a series of reasons.
They interact with each other fine, no real problems there, except Mastodon users can't see custom emoji reactions and such.
Mastodon apps generally work fine with Akkoma, for Sharkey it is a bit less smooth and also a lot of the extra functionality of Sharkey is obviously not supported in Mastodon apps.
Sharkey includes many improvements that never made it back into the Misskey codebase and Misskey's documentation and community support is mostly in Japanese.