I was given to read Linux and the Unix Philosophy by Mike Gancarz. The work was published back in 2003, and I understand it to be a sequel of The UNIX Philosophy published almost a decade earlier.
The book is mostly philosophical (surprise, surprise), and an interesting read from a historical point of view. It brought me back in time to the good old age of Linux Kernel 2.0.0 and the like. While some of the truths described are timeless, many are just outdated, historical perspectives. Examples: the author advises to resist the temptation to rewrite shell scripts in C... While relatively few people would have tried rewriting scripts in low-level languages back in 2003, nowadays, with an advent of modern dynamic scripting languages such as Python and Ruby, the point is simply moot. So is convincing people that printing source code on paper is suboptimal. There are very few people in this world who still wouldn't realize it. On the other hand the book doesn't seem to talk too much about aspects of scalability and robustness. The author rightly points out that "The philosophy of one century is the common sense of the next". Yeah, in this case it's hard to disagree.