If that's not geeky enough, you can read the spec for the browserid protocol: https://github.com/mozilla/id-specs
Comparison to OpenID is covered in the FAQ page: https://developer.mozilla.org/en-US/docs/Persona/FAQ#How_doe...
We've got a list of recent talks, too, in case you'd rather flip through slides or watch a video: https://wiki.mozilla.org/Identity/Spread_Persona