Lemmy is similar to sites like Reddit, Lobste.rs, Raddle, or Hacker News: you subscribe to forums you're interested in, post links and discussions, then vote, and comment on them. Behind the scenes, it is very different; anyone can easily run a server, and all these servers are federated (think email), and connected to the same universe, called the Fediverse.
This is a list of Free Software network services and web applications which can be hosted locally. Selfhosting is the process of locally hosting and managing applications instead of renting from SaaS providers
A curated list of Docker resources and projects