There are three things I like about this book (well, lots more than three, but I only have a foreword's worth of words to work with).
One: It's concrete. Extreme Programming Explained is a manifesto, a call to arms. "Hey gang, over there might not be so bad." The problem with manifestos, as history shows, is that execution of them is often fraught with difficulties (or outright impossibilities) that are not obvious from ten thousand meters away.
Extreme Programming Installed is all about really doing it—programming extreme. Here you will find a hundred little techniques for making the high-minded ideals of XP real and practical. And they are concrete, so you'll know from the first minute whether you are doing them or not.
Two: It's from ...