Imagine if you could follow an Instagram user from your Twitter account and comment on their photos without leaving your account. If Twitter and Instagram were federated services that used the same protocol, that would be possible. With a Mastodon account, you can communicate with any other compatible website, even if it is not running on Mastodon. All that is necessary is that the software support the same subset of the ActivityPub protocol that allows for creating and interacting with status updates.
Mastodon is a fascinating project. At surface level, it is similar enough to Twitter for people to consider it a valid alternative: the UI and the fundamental social constructs could not be more familiar. At the same time, you don’t need to dig too deep to encounter esoteric concepts like ActivityPub and the fediverse.
A common viewpoint is that Mastodon has failed to appeal to a broader, less tech-savvy audience so far due to its federation model, but I tend to disagree: after all we are using federated messaging systems every day and we’ll likely keep doing so until the end of time.
There was a moment when email itself was an esoteric concept and it was important to know what SMTP is in order to send a message, but we have managed to abstract all that complexity away, so I am cautiously optimistic about federated social media in the long run. Arguably the biggest challenge so far is the network effect (or lack thereof), as it’s hard to move to a new platform when all you friends are somewhere else. In that respect, feel free to follow me @email@example.com. Don’t be shy!