This is actually why I posted this. It seems PLATO has never gotten its due for the truly revolutionary concepts it introduced. I remember - in the early eighties - playing networked games and participating in tournaments, sending "personal notes" which were emails, participating in discussion forums with people from universities all over the world, taking lessons to augment my schoolwork...There was even instant messaging. All from a PLATO terminal which was made out of wood and metal and connected to the university mainframes at 1200baud.

I dunno about that. I walk by a nice little wall display about it whenever I'm at Siebel.

> Is TCP/IP really what makes the internet the internet

Yes, because the Internet is the Internet because it's a network of networks, all sharing the same protocols, all routing data among each other via gateways using packets. Networks existed before Arpanet, before PLATO, but it wasn't possible to cheaply interconnect networks and send messages end-to-end before TCP/IP.

Removing TCP/IP and the concept of the gateway from what it means to be the Internet doesn't mean PLATO is first. It means some even earlier computer network is first, and PLATO is still a footnote in the history of the Internet.

That's a great response had it been to a slightly different comment... But what I think you're trying to say is that the gateway (IGD) allowed the internet to grow much faster than PLATO was capable of and that growth is part of the character that defines what the internet is.

I'm saying that the Internet is defined by being an internet. An internet is a network composed of multiple independent networks with independent low-level protocols which share data using a higher-level protocol suite. The higher-level protocol suite for the Internet is TCP/IP, so, yes, TCP/IP defines the Internet.