@cedarmesa@c2h6
Diaspora is one of the oldest of the oldest. Much older than mastodon. They’re federated too, but not on the same network.
Mastodon and lemmy uses ActivityPub. (Mastodon used to run on OStatus, but then switched to ActivituPub later) Diaspora uses its own protocol and refuses to ever switch to a most recent one.
Some fediverse services however (friendica and hubzilla which are kinda facebook-like) are using multiple protocols and can federate with both mastodon and diaspora.