I created a proof of concept of a booklist in OPML, both human and machine readable, that can point to other people's lists as well for discovery.
@emacsen machine readable as in https://en.wikipedia.org/wiki/Machine-readable_data The opml is structured data, where each node has a range of data attributes (which mostly also follow schema.org), and can be machine read (such as trivially by it being processed through a XSL template). (The data structure is not visible in the html rendering or when imported into a default opml reader though. But view source in the html rendering shows the data structure) Or do you mean something else?
It's machine parsable, but I'm asking about the issue of semantic meaning.
This gets somewhat "theoretical" because what does semantic mean. Is OpenStreetMap data semantic? It depends who you ask.
But what I mean here is essentially Linked Data. Is there a way I can say "When Tom says book and Alice says book, they mean the same thing."
We can do that in something like JSON-LD, or in an RDF, which has an XML representation. That's sort of the last loop of semanticness.
@emacsen Ah I see. I'm not after linked data. I'm after machines reading it, parsable. It is structured data otherwise, the data attributes in it use standard definitions (book is a schema.org type e.g. with defined attributes) where possible, so could be connected to other sources using the same thing. My file doesn't currently point to schema.org yet, but should, yes. All linked data is machine readable, not all machine readable data is linked data.
@emacsen Similarly wrt 'federated', I use the term because the original blogpost by someone else that triggered mine used it. 'networked' is probably better, as it doesn't carry fediverse overtones. In this case networked is that you can include lists directly from other sources into your own list at any point, as a branch on your tree structure, and point from any book node to another list as where one found it. This is not a linked data link, but a discovery focused link.
Ton's personal Mastodon instance