Nice writeup by @darius about Dat, SSB, and ActivityPub and how they can learn from each other: https://blog.datproject.org/2019/03/22/three-protocols-and-a-future-of-the-decentralized-internet/
Indeed, my post-standardization of ActivityPub work (on Spritely) has largely been about exploring similar thoughts! See also the @librelounge episode with @joeyh where we talk about Secure Scuttlebutt (esp in relation to ActivityPub) https://librelounge.org/episodes/episode-14-secure-scuttlebutt-with-joey-hess.html