There are many alternative social networks, here is a short list with some comments from my experience:
- Mastodon: A decentralized social network. You can join a community or create your own.
- Diaspora: A decentralized social network. You can join a community or create your own.
- NextDoor: A centralized network with local community focus.
- Steemit: A blockchain based social network.
- Minds: An anti-facebook blockchain based network that would possibly end under the topics menu on unweb.dev.
If you use another social network, please post about it in the comments.