In the beginning there was diaspora and its $200k kickstarter. That got things going and still exists today but its on lifesupport. Mastodon was the second wave that showed a federated microblog that looked good and federated 'well enough' was within our grasp. Then activitypub came and standardized certain federated interactions with a modern style over ostatus. Mastodon usage climbed slowly and suddenly there were 2 and 3 and 4 federated projecs in development. Mastodon is the federated twitter. Pixelfed is the federated instagram. Peertube is federated youtube with an amazing clientside bittorrent player. My single mastodon newsfeed incorporates updates from people on all those services. Any of them are available to install yourself if you wish to manage your own copy.
The Fediverse has Landed