The lemmyverse sounds perfect, but it ignores alternatives like kbin etc. It would be better if we didn't end up with the situation we have with Mastodon where people assume Mastodon is the fediverse.
So, what do we call this little niche in the fediverse?
The Fediverse. There's nothing inherently special about Lemmy or kbin or lotide being link aggregators. We get regular posters from Friendica and I've gotten replies from Mastodon accounts before.
The Fediverse is ALL of us. We should be interacting with PeerTube and Misskey and all the rest!
Can I ask then: on the Fediverse, what distinguishes something like Lemmy from kbin? They can presumably...federate with each other, so what's the distinguishing factor? Is a Lemmy instance fundamentally different in some way than a kbin instance (I only just found out about kbin and originally though it was a Lemmy instance, but now I'm not sure).
Disclaimer: I am not a dev, my technical understanding is limited, and I only discovered kbin today.
The difference is that they are running completely different software, despite speaking the same* language ('protocol'). There may be some things one software does that another can't. I wonder if it's easier to answer what distinguishes it, or what makes them similar. They're both link aggregators (the same kind of website as reddit, e.g. people post links to groups and they get voted up or down by subscribers), and they're both able to process each other's posts and see each other's groups (kbin calls them magazines, apparently, while we call them communities. I don't know if that's purely semantic or if there is a profound difference). So as far as basic usage goes, both can make a post and unless they do something fancy, the other site can read and reply to it.
kbin has a different visual layout and appears to have more focus on also having microblogging and social media features within those groups, we don't have that feature and integration with Mastodon can be a bit stranger here (such as them replying to replies, in my experience it doesn't nest neatly like ours do, instead just showing as a reply to the original post, and maybe that's unavoidable when a twitter-like thread without proper comment replying has to fit our comments layout). It seems Lemmy has stayed closer to what reddit is like, while kbin has strayed into a more experimental approach.
kbin says "This is a very early beta version, and a lot of features are currently broken or in active development, such as federation" (and I have noticed the federation doesn't show some posts yet which would be expected to show). Lemmy doesn't seem to have such disclaimers. It's current version number suggests it is considered more mature, but still not particularly stable either.
kbin seems to have a mobile app under development, while Lemmy's seem to be more mature. That said, I've never used one.
Short version. Kbin is like gmail, lemmy is like outlook. They both present things in a different way and have completely different code bases, but they both do the se thing, email.