01 / The short version
Open a browser. You land on a desktop.
It looks like a computer from the era before computers started spying on you. Winamp is playing. There's a start menu, icons, windows you can drag around. But this desktop is not yours alone. Everyone who enters Deck 59 lands in the same room. The person three icons over is a real human, right now, and you can talk to them, trade with them, and hand them software without either of you downloading a thing.
That's the whole idea. Everything else is detail.
