Something that never gets built because the project scope is too ambitious and ambiguous...
The World Wide Web was preceded by Project Xanadu [1] which, despite a decade of significant investments from both research institutions and private companies like Autodesk, never reached a stable state where it could be actually used for something by people outside the project's inner circle. The WWW got there just a few years after it started.
Tech people often forget that for many global scale projects, the actual /technical/ problems to solve are only about 5% of the overall project. The political problems (political meaning conflicting interests of different parties involved) are much harder to solve.
Having studied both, I love tech because 1+1=2 always. I find politics much harder because --depending on the way you present a problem-- 1+1 maybe anything between 1 and 3, and sometimes even 20.
The World Wide Web was preceded by Project Xanadu [1] which, despite a decade of significant investments from both research institutions and private companies like Autodesk, never reached a stable state where it could be actually used for something by people outside the project's inner circle. The WWW got there just a few years after it started.
[1] http://en.wikipedia.org/wiki/Project_Xanadu