Xmonad is a tiling windowmanager for X, running on various systems including GNU/Linux. This video was shot on Arch Linux.
Almost everything in Xmonad is done with the keyboard, a mouse is not needed. The only time I use it in my video is in gimp.
Xmonad places the windows and makes sure that they use the screen as good as possible. You don't have to worry about resizing windows, xmonad does this for you. Everything is predifined in a configuration file.
Configuring Xmonad can be a bit hard, so check out my blog where I have a guide as well as my own configuration files.