GoToSocial is a new kind of Fediverse server which emphasises user safety, and is currently under development in alpha testing. If you’re a techy person, you can find out more from the official GoToSocial technical documentation site ⧉. It is still in its very very early stages though, not ready for prime time yet, and they would appreciate support in order to get to a release version more quickly ⧉.
The aim of GTS is protect users from trolls and other nasty people through either traditional blocklists or allowlists instead. Allowlists mean that all other servers are blocked automatically, and only servers specifically named in the allowlist are allowed access. Allowlists are the safest possible option for a federated server, though they do make it harder to discover new servers. It’s up to a server’s owner to decide where the balance between safety and discovery lies, and GTS aims to give them more options when deciding on a good balance.
GTS is also unusual because it doesn’t include a website interface, it can only be used through third party apps. Fortunately, it supports the Mastodon API which means it can be used through any Mastodon app, and there are lots of those for all platforms ⧉.