Below is a list of free software that you can run and create your own link posting site or a social network.
- Whaller: Create private social networks — ad-free and respects your data rights
- Postmill: Postmill is a straightforward link posting system — see it running as Raddle
- Mastodon: A twitter alternative
- Notabug: Free software that runs an old-school reddit-type system — (not to be confused with NotABug.org)
- Tildes: A self-hostable online bulletin board. The code is licensed under GPL 3.0.
- Akasha – A decentralized online bulletin board using IPFS and Ethereum.
- Lemmy – A self-hostable link aggregator intended to work in the Fediverse.
- MeWe: Create a social network in a privacy-respecting environment
Some of these servers have public instances running — note that these communities are often uncensored and libertarian-leaning.