A Letter to All Present and Future RSS Syncing Platforms (2014)

This seems like an unsolved problem to this day. Does anyone know about any active efforts to define an "Open Reader API" of any kind?

I have been thinking recently that it would be _great_ to have a simple server that handles your RSS/podcast subscriptions and keeps track of the read/undread status, either as a simple linux deamon or maybe even as a serverless (decentralized / IPFS / OrbitDB) sync solution. Then anyone could make apps for any platform on top of it.