After watching the two Doctor Who Christmas episodes I thought I’d watch the ‘behind the scenes’ programme ‘Doctor Who Confidential’. During one segment where they discuss the set used in the Christmas episode I spotted a bunch of machines with what look like Ubuntu boot screens on them. If you’re in the UK (or have access to Freesat in Europe) you can see it on BBC HD at 16:55 on 3rd January, or on BBC Three at 04:10 on 5th January. according to the iplayer page. The frame below was grabbed from 38:29 mins in.
They look like Ubuntu 6.06 (Dapper Drake) to me. Probably multiple screens connected to one computer as they are all showing the same thing in the actual episode itself.