Open Library is one of the main data sources for Bookwyrm’s book data. Bookwyrm is an application in Fediverse that can be used to find and write reviews of books. I wouldn’t see that as a contradiction.

Sharkey is also for microblogging but it also has some extra features, including user sites that can be used as a kind of blog and it “can play module / tracker music files - can play Flash (swf) - (federated) listenbrainz integration, …”

I haven’t tried these functions yet