He's running X with a minimalist tiling wm with only one window at a time, not trying to live through a VT100.
Of course, some Hackernews is now going to tell me about how this setup falls down hard when you need to do real work and how sensible people just use KDE or GNOME -- or Windows.
Personally, I like having a few widgets on-screen all the time - a clock, a volume control - and I enjoy having two or three things open on-screen: a terminal and a browser, for instance, or two terminals ssh'ing to different machines. Having lots of display area helps. Pretty much every window manager can handle this, and it's just a matter of figuring out which one gets out of my way fastest.