mod_rewrite is a powerful tool, but, unfortunately, it has always been poorly documented and its somewhat arcane syntax makes things even worst. Bowen offers a very welcomed alternative to the obscure official documentation. Be advised a decent understanding of Regular Expressions is required to fully leverage mod_rewrite

When I first came across RewriteRule directives I was mostly horrified. It was only because I was learning about Perl Regular Expressions at the time that I didn't make the sign of a cross at the stuff and just go another direction. But I realized that the power I craved came at a cost.

I admit that I had did the whole "trial and error" thing coupled with scouring the net for examples before I realized having a book would make things so much easier. So I resorted to searching Amazon for mod_rewrite. This is the only book that my search turned up.

I have to say the book was definitely well worth it. The tips about when to NOT use mod_rewrite was very much appreciated. Some of my uses could have been accomplished with a FilesMatch or DirectoryMatch directives instead of a RewriteRule.

The VirtualHosts chapter was useful, as was the Proxy chapter. I didn't realize how useful mod_proxy was until this chapter gave a few good examples.

All in all I'm very satisfied with this book. Because of the short length I was worried that it wouldn't cover the material well enough. However I don't think there is anything I've needed to do with mod_rewrite that this book didn't cover well enough for me to accomplish without another resource.

Having only about 140 pages, I wouldn't call this 'The Definitive Guide'. Even though I read it cover to cover and mod_rewrite is a relatively small subject, there are still some unanswered questions.
Still, the book contains easy to read explanations, a quick primer on Regular Expressions, recipes, and - very important - examples of problems that should NOT be solved with mod_rewrite because there is an easier way to do it.
So for those that are no experts yet and thus far had to consult the (not very user-friendly) official documentation on the Apache website, this book is certainly a good introduction.