(This is a continuation of my comment to @cjs Go-Fed: Past, Present, and Future best addressed in a separate topic)
The future of the Fediverse where we go way beyond fixed, still micro-blogging-like AP extended apps to support for rich Linked Data based domain-specific apps could be the absolute killer feature of the Fediverse.
Right now any app with significant domain-specific AP extensions needs to squeeze into a ‘microblogging jacket’ to achieve federated interoperability (i.e. you better have as:Note somewhere in there). The lowest common denominator determines the federated capabilities.
@cjs in your APConf presentation at 35:15 you talk about federating the vocabulary schema’s themselves, and even go a bit further by federating ActivityPub “flavors” (e.g. ‘webfinger+HTTP-signatures’ vs. ‘OCAP+Tor’, etc.). That’s some really interesting stuff, and goes way beyond NodeInfo and the bit clumsy ‘temporary convention/workaround’ of having FEDERATION.md docs.
Would love 
to know more about your ideas in this regards, and to get a discussion going.
I posted about a related issue in the Solid forum: Aligning efforts in LD schema / ontology design + adoption.
When it comes to what is out there on the web in terms of linked data, one can only conclude that it is a big sprawling mess. It is really hard to get good ontologies together in an application, and - after doing so - avoid creating your own unique interpretation of the semantics within.
There’s interesting insights provided by the devs of TerminusDB, which uses OWL-based schema’s just like go-fed does:
For schema design, TerminusDB uses the OWL language with two modifications to make it suitable as a schema language. Namely, we dispense with the open world interpretation and insist on the unique name assumption. This provides us with a rich modelling language which can provide constraints on the allowable shapes in the graph. We really support OWL as it is logically expressive.
Finally there was also this nice tool for visualizing schema’s, called Web-VOWL (and other tools at VOWL).
Based on that thread some Solid members are looking into building a Solid List of Vocabularies app, where vocabs stored in personal data vaults (POD’s) are synchronized to collection hubs.