Around the time Mastodon entered the room, ActivityPub was already brewing in the background. Why?
1. @evan wanted to take pump.io lessons learned to the W3C
2. @cwebber wanted federation in MediaGoblin
In the end, ActivityPub almost didn't become a W3C recommendation due to time constraints if it hadn't been for the fact that
3. @Gargron wanted better privacy controls and federated DMs in Mastodon, and less papering over the gaps in OStatus