Is there a fairly comprehensive open bibliographic database out there?

Why do I want to know?

• Situation: I want to reference books in my blog, in my notes, in my books, in my essays.
• Complication: to do this I usually have to manually search for the books, then extract metadata (using e.g. zotero), then export to bibtex, then merge into my file and check there are no id conflicts, then reference in article or piece, then use special tooling to convert that opaque identifier into something pleasing to the eye.
• Question: is there a tool that would do this more efficiently? If not what would I need to build one?
• Answer: I would need a bibliographic database that was open and I would need to build a tool.
  • Building the tool would be relatively easy if you had the database.

So: could one build a proof of concept with what is out there?

Other comments:

• I want nice identifiers. The kind of things where I can guess what this is without having to lookup.
• Can we focus on the top titles. We don't need an id for every book to start with.
• In FRBR terms do I want works or expressions? Probably expressions but maybe also works?
• What is the minimum we can do?

Note: bibliographic database would serve a lot of other purposes …