The InternetProtocol does not provide any value-added logic in between the transmitter of information and its intended destination. Rather, all the content-level logic is done at the ends of the network. This means that the network is not biased to one application or another, but rather it is merely a transport mechanism for whatever anyone wants to put on top of it. Thus, no one ever has to ask for permission to run an application on the network, and the network is already ready to handle new types of applications without ever needing to be upgraded. It's better to think of the Internet as a RoadNetwork. As long as you have something that rolls and you can steer, you can put almost anything on the RoadNetwork. Moreover, you can have any purpose for driving on the road, be it for taking the family to the beach, for trucking lumber, or for moving military vehicles. The roads do not care.
Isenberg, D. (1997). The rise of the stupid network. Computer Telephony, August 1997, 16-26. Available from http://www.hyperorg.com/misc/stupidnet.html
Saltzer, J.H., Reed, D.P., Clark, D.D. (1984). End-to-end arguments in system designn. 'ACM Transactions in Computer Systems, 2(4), 277-288. http://www.reed.com/Papers/EndtoEnd.html
Searls, D. and Weinberger, D. (2003). World of ends: What the Internet is and how to stop mistaking it for something else. Available from http://www.worldofends.com.