I actually just discovered Outline yesterday! It's an awesome platform. Our feature set isn't as extensive (yet), especially when it comes to integrations—they've really nailed that. However, many of the other features, like live collaboration and better security, are things we're actively working on and should be available in the next few releases.
One major difference between Outline and Kalmia is the license. I believe Outline uses BSL, while Kalmia is AGPL.
We self-hosted Outline like two weeks ago in our company (15 people) and the acceptance is overwhelming positive. We tried different tools in the past: WikiJS, XWiki, docuwiki, Bookstack and there was quite a big resistance in using it. Main reasons where like, missing core functions e.g. no live collaboration, no e-mail notifications on commenting, no diagram functions, strange rules regarding page organisation, etc.
Outline feels mentally really lightweight but checks all boxes that we searched for. Some people says its quite similar to Notion, but without the automatisation stuff (I have no experience with Notion).
