There's quite a few, and most of them federate with one another. What's interesting is that Reddit isn't really a single community - Each individual subreddit

There's quite a few, and most of them federate with one another. What's interesting is that Reddit isn't really a single community - Each individual subreddit has it's own moderators, editorial voice, group of people, etc. They can each move independently. For example, /r/startrek and the related startrek websites have all moved to https://startrek.website https://startrek.website This federates with Lemmy, kbin, etc - So if a user posts to startrek.website it shows up everyone else's servers, and people can reply from whatever federated site they use