tmux 2: Productive Mouse-Free Development

If you've been using tmux, you can skip the first two Chapters. If you don't plan on using tmux for pair programming (which I'm guessing most people who use tmux won't do), you can skip 5th Chapter. The other 3 chapters were fun and taught me a few bits.

Overall, it's more of a long article than an actual book, so I can't judge it too harshly. It's not a bad way to spend an hour or so, it's a very quick read.