Rework, by Jason Fried and David Heinemeier Hansson, cannot accurately be described as the "sequel" to the first book to come out of 37 Signals, Getting Real. As a significant percentage of the book seems to be word for word identical to text in Getting Real, I think it's more of a "remix." Getting Real focused on creating marketable web software, whereas Rework changes the focus ever so slightly to growing a business around marketable web software.
If you've read Getting Real (you can sample...