What If OpenDocument Used SQLite?

I love SQLite.

As a document _exchange_/_interchange_ format, what I prefer for durability is a non-binary format (e.g. XML based).

For local use, I agree SQLite might be much faster than ZIP, and of course the ability to query based on SQL has its own flexibility merits.

XML isn't great for exchange/interchange either due to security problems and inconsistencies in implementations. A big part of the problem is that xml has a lot of complexity, which leads to a bigger attack surface when parsing and processing untrusted data. And then xml entities are just inherently insecure, unless you disable some of their capabilities (like using remote files, and unlimited recursion).

That said, creating a format that can convey rich untrusted data is a hard problem.

Part of the problem though with saying SQLite instead of XML is a lot of things would lend themselves to XML in SQLite.