I've been trying Lemmy. Lemmy is a similar idea to Reddit, but it's federated. What 'federated' means is that there isn't one Lemmy website; there are a lot of them (instances) and they all talk to each other. It's a distributed discussion platform.

The idea is that each Lemmy instance is responsible for a set of users and a set of communities. To you as a user, you pick an instance to sign up with and you can then access communities on any instance.

I have a couple of thoughts.

Firstly, at the moment the usability is a bit wonky due to the federation. The front end could use a bit of work in making it easier to discover and access communities cross instance - as well as preventing you from clicking a link and ending up on another instances on which you don't have an account and are therefore logged out. The actual technical federation also causes confusion as remote community data appears to be stale sometimes.

I think these are just technical growing pains and will be resolved in time with a larger audience and more feedback. Though, I am a little surprised that the users are per-instance rather than global. I see the logic of keeping everything decentralised and per-instance, but dare I mention that Bitcoin has proved that you can build global, decentralised databases.

Secondly, the nature of federation is both good and bad. On the positive side it means that no commercial entity thinks it owns your data and has a right to do with it as they like (as we've recently seen with Reddit). On the negative, it means that any individual community or individual account is stored on only one single Lemmy instance, which may just disappear without warning one day. I hope that some redundancy can be built in to prevent this.