I was going to ask if someone could give this discussion a more informative title, but then I realized the linked website is not going to be around for long.
If they've actually sought permission to be displaying and re-distributing all those manuals, they don't make note of it on their site anywhere. In today's world that means A) they're not too bright, and B) they probably didn't bother.
From the first substantial paragraph of text from the first of many HP manuals:
"No part of this document may be photocopied, reproduced, or translated to another language without the prior written consent of Hewlett-Packard Company."
I predict they'll be forced off the web as soon as they start attracting attention.