The goal of Kbin is to communicate with many other ActivityPup services.
Lemmy: Link aggregator, social network, forum
Kbin: Link aggregator, social network, forum, microblogging
Mastodon: Microblogging
You can use Kbin to interact with Lemmy, Mastodon, Pleroma, Peertube, and others. That's why I switched today (and loving it, exploring everything right now).
I don't believe that there are multiple instances of Kbin right now. I only know of kbin.social (it is free and open source, though, so anyone can open another instance, I think). Edit: This was wrong. There are many instances. See the answer below.
I had exactly the opposite experience, I joined a kbin and a lemmy instance and opened communities in both, definitely found lemmy easier to jump on too, and lemmy for me was more stable by a large chunk , but that might be the instance I am on seems very well run.
Ernest, from what I've seen, has been very receptive and passionate about all the incoming users. They scaled their infrastructure quickly to meet demand and were interacting with users on kbin regarding features they would like to see. I have high hopes.
AFAIK kbin is way early in development and got slammed by a wave of new users after Rexxit happened.
So the dev’s priority right now is server and platform stability, and it’s already way smoother than it was a couple weeks ago. That being said, there are a ton of features planned and development seems to be going pretty quickly at the moment
The site is very new and is in active development. For now, it's mostly under the hood stuff but the stability of the experience increased quite a bit since I first started a week so they must be doing it right.
I believe the owner @ernest is doing the heavy lifting by himself.