Can anyone explain what Disciplined Agile Delivery actually is?

I've been learning about various software development methodologies, and by far the least transparent of them has been DAD. The Wikipedia page appears to be written by the author of the approach and is full of jargon. Other resources I've found mention frequently that it's a hybrid of other approaches, but don't seem to say how it implements those approaches, or what it actually does.

I'd appreciate either an explanation or a decent resource explaining what DAD is, if anyone's familiar with it.

Cheers!