Aside from the aforesaid problems with the book's companion site, there are a few other areas for improvement: It was noted earlier that the last appendix contains the sample code from chapters 15 and 17. The author states that these code listings were located in an appendix, rather than the chapters themselves, because they are too long. Actually, they comprise only a dozen pages, which would have been better located in the chapters where the reader expects to see them, and where they would be close at hand for referencing. The first listing is only two pages long, and definitely should be located in chapter 15. Even for the second listing, if the author is concerned about readers getting frustrated flipping through the 10 pages to find the continuation of the chapter's discussion, a simple note at the beginning of that code, as to what page the discussion is resumed, would be sufficient.