mastodon.social is one of the many independent Mastodon servers you can use to participate in the fediverse.
The original server operated by the Mastodon gGmbH non-profit

Administered by:

Server stats:

380K
active users

Eugen Rochko

What this means in practice is that some branding was slapped on the frontpage, profiles were broken to be unviewable while logged out, federation with other Mastodon nodes was broken or disabled, and IP addresses of countries like Russia, Iran and China were added to their Cloudflare block settings.