The days of OStatus are numbered. The venerable protocol has served as a glue between many different types of servers since the early days of the Fediverse, connecting StatusNet (now GNU Social) to Friendica, Hubzilla, Mastodon, and Pleroma.
Now that many fediverse platforms support ActivityPub as a successor protocol, Mastodon appears to be drawing a line in the sand. In a Patreon update, Eugen Rochko writes:
…OStatus…has overstayed its welcome in the code…and now that most of the network uses ActivityPub, it’s time for it to go.Eugen Rochko, Mastodon creator
The pull request to remove Pubsubhubbub and Salmon, two of the main components of OStatus, has already been merged into Mastodon’s master branch.
Some projects will be left in the dark as a side effect of this. GNU Social and PostActiv, for example, both only communicate using OStatus. While some discussion exists regarding adopting ActivityPub for GNU Social, and a plugin is in development, it hasn’t been formally adopted yet. We just hope that the Free Software Foundation’s instance gets updated in time!