I came around this again today, as I follow https://mastodon.social/@hyperjinx and he seems to use this service:

…I was then wondering, if micro.blog is maybe just hosted matstondon; or more general: “what’s behind it”?
sadly nighter micro.blog nor http://help.micro.blog/faq/ gives any information in that (more technical) direction. (But I might not be target group, so that’s ok).

So this brought me here agein, and it’s nice to see:

Thanks for that link!