Google Translate:
First of all, the ActivityPub system is not suited to something like Misskey, which flows at lightning speed.
It was originally designed to connect blogs, small-scale SNSs, and wikis.
How can it handle the TL hell where tens of thousands of requests fly in per second?
It’s based on the idea that it would be nice if various small services could send each other updates, so it’s quite costly.
It is a microblogging plateform of the fediverse. They are as of today two major microblogging software on the fediverse : mastodon and misskey along with its many fork (forkkey or *key) : firefish(previously calkey) iceshrimp, foundkey.
There is of course other microblogging software but mastodon and the *key family seem to me to be the most active.
Thanks! Is it similar to tumblr or mastodon or is it not like either of them in terms of format?
I’ve used Calkey and Sharkey and they quite similar to Mastodon but with a prettier UI. I don’t know Tumblr so I can’t say.