no AP is not the right protocol for shared/collaborative systems, the creators of forgefed have the same thoughts: https://forgefed.org/blog/actor-programming/.

It doesn't feel to me as if the author of that really get AP.

AP fundamentally rests on exchanging activities, that model operations on objects in collections.

Everything under their "basic concepts" section can map cleanly to an application that speaks AP.

AP has actors. Methods maps to Activities. Making networking transparent is down to wrapping things in a local framework that chooses when to use networking. Their concept of "vats" similarly is down to a lcal framework that calls method if local and posts AP activities otherwise.

AP provides a format for storing both the activities and other objects to disk, but you can choose to use your own, and that includes state that might reference other actors.

I'm working on an app server, in fact (not open source) that is based around those concepts and provides all of the things they're describing, but currently with AP as the main external protocol (that is likely to change - e.g. we're likely to use NATS for communication internally in clusters of these app servers).