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:

336K
active users

John Gruber

I like the fact that mastodon.social is the biggest instance, but I would leave for an instance that is paid only, say $10/month, has a cool domain name, and thus can afford to raise the rate limits.

Mastodon.social feels like early Twitter both culturally (good), and fail-whale-wise (not good).