This server isn’t the only one I’m running in the Fediverse :-) I’m currently running these:
https://lemmy.world: You’re looking at it.
https://mastodon.world: My largest server, over 160.000 users.
https://musicworld.social: Another Mastodon server about 1 of my hobbies
https://pool.social: Another Mastodon server about another hobby of mine
https://fotofed.nl: A Pixelfed instance
https://calckey.world: A Calckey server. A bit different from Mastodon.
https://fediland.nl: A Misskey server. Calckey is forked from Misskey, personally I like calckey better.
https://play-my.video: A Peertube server
https://akkoma.nl: An Akkoma server (kind of lightweight but fully featured Mastodon)
https://ruud.social: Akkoma server just for me
https://blog.mastodon.world: My writefreely server, yes that federates too.
More to come probably…
Well running them all is easy, I mainly use Docker for running them, which makes it easy. I just hope all platforms will be developed to maturity, and they will all follow the activitypub standards so they can communicate with each other. Now, some platforms implement features a bit differently from eachother.
I didn’t make mastodon.world grow so much, it just happened to me. Mainly thanks to mr. Musk. Details on that are here: https://blog.mastodon.world/and-then-november-happened