Looking for alternatives to Twitter microblogging. Mastodon seemed cool but has its downsides. Pleroma purports to be lighter-weight to host and fully ActivityPub compatible. What's the catch?
(I am not very experienced with the fediverse, having only just joined Lemmy)
Seems pretty good, you should probably just give it a try and see which one you prefer.
https://joinfirefish.org/join/ is also an option (I like it better than Mastodon, but to each their own)
I would go with Akkoma over Pleroma but that's just me. I also like what I see in Calckey (Fire Fish). I like how Fire Fish allows the data migration of follower/following lists and posts. Feature-wise, Mastodon is falling behind a little but I am ultimately satisfied with the platform and I have a lot of time invested in learning it and maintaining it. Rather than learn a new platform, I need to invest my energies in a web development class so that I can make my escape from a miserable career in desktop support.
If you just want to join an instance, it doesnโt really matter if they are running Mastodon, Pleroma (or one of the forks), you will be able to follow and interact with everyone else on the microblog portion of the Fediverse. In fact from a Kbin instance you can do Lemmy communities and Mastodon microblogging from the same platform (Kbin calls communities Magazines and in the magazines are Threads, and they call the mastodon-like portion is just called microblog).
If you want to self-host your own instance, then you need to pay attention to the difference in the platfoms, Pleroma is lighter, Mastodon is more modular, and there are many forks of both each with their own strenghts and weakenesses.
If you don't like the frontend, you can use Elk, or Soapbox, or some others out there, as well as all the apps and PWAs for either platform, most are compatible with both.