Mastodon is more Twitter-like; Lemmy is Reddit-like; KBin has elements of both (Magazines and Threads being more Reddit-like, Microblog view being vaguely like Twitter). Mastodon has had a couple of big influxes of people considering leaving Twitter, similar to how Kbin and Lemmy are getting a lot of interest considering leaving Reddit.

What’s intriguing is that because they all use the same protocol (ActivityPub), people on Kbin can vote and comment on Lemmy posts, and Mastodon users can comment on Kbin or Lemmy posts. This is called federation, and software that uses ActivityPub is considered part of the “fediverse”. There are also dozens of other fediverse software platforms – Pixelfed is Instagram-like, Bookwyrm is goodreads-like, micro.blog and WriteFreely and others are blogs, etc etc. – that can all all interact, at least somewhat. Of course the reality’s more confusing, sometimes you can’t interact between different sites or software, and sometimes interactions are limited (for example you can’t vote on Kbin or Lemmy threads from Mastodon).

Here’s a post I made a few days ago from a Mastodon account that’s also visible in the Lemmy fediverse community, because I tagged the community. It didn’t go to Kbin (even though I tagged a Magazine) because federation wasn’t working at the time; and some of the replies in on Mastodon went to Lemmy as well, others didn’t, who knows why. Oh well. Still, it’s amazing when it works!