After a quick read, to me the difference vs. something like IPFS+IPNS seems to be the quasi-"federation" angle, such that Upspin acts like a protocol you can re

After a quick read, to me the difference vs. something like IPFS+IPNS seems to be the quasi-"federation" angle, such that Upspin acts like a protocol you can retrofit into an existing content store instead of self-hosted software with its own "captive" private datastore. For these reasons, I find it conceptually most akin to BitTorrent when combined with Magnet Links that are shared by strongly-authenticated identities than to any other distributed content store project.