relaton

https://github.com/relaton/relaton

Relaton is the database, registry, and cache for bibliographic references to technical standards in the Relaton/XML bibliographic model. It provides the Relaton::Db API, a registry that lazily loads each standards-body flavor (ISO, IETF, NIST, IEC, …) on first use, and a file-based cache. Every flavor ships inside this single gem — `gem install relaton` gives you the full multi-flavor setup, with flavor code loaded on demand via autoload. The CLI (relaton-cli) is a separate gem.