Seems that my comment is controversial as someone has voted me down. I'm curious to hear from opposing views - I love technologies like TCP/IP, gcc, Unix, C, etc. - but I think they wouldn't be much use unless they were used to enable applications like Twitter, Google, Nethack and Wikipedia.
I do want to clarify that I'm not saying that the underlying technologies aren't amazing.
I think the debate is whether TCP/IP would be useful without Google, or Wikipedia would have happened without TCP/IP. Personally I would say that IP changed the way people think about information, which made Wikipedia seem plausible.
I do want to clarify that I'm not saying that the underlying technologies aren't amazing.