I see that at http://blog.gleam.io/hipchat/ is talked about "Public Chat Rooms" which I see you can open and participate through a web page, without signing in HipChat, by just choosing your nickname (Full name as they say on the page. Actual chat room is at https://www.hipchat.com/gXGrGMHTO .
How can you create a public chat room on HipChat that is publicly accessible?
Best Answer
Stuart McKeown helped me out. You have to:
Note that you have to be Admin to be able to allow guest access.