Right, others have mentioned the WWW. But it doesn't look obvious to me how the existence of a high energy physics research facility was a necessary preconditio

Right, others have mentioned the WWW. But it doesn't look obvious to me how the existence of a high energy physics research facility was a necessary precondition for the development of the web. The idea of hypertext had already been floating around for some time (SGML, Xanadu, etc). I was curious about things more directly related to the actual research done at CERN.