This is a book about Regular Expressions 'for Perl and Other Tools' but really it's a book about Perl. Other tools are covered, but coverage is a bit woolly, so if you are reading it to get the low-down on Python's RegEx capabilities etc. this book won't get you far. I can't help that feel that if the book had just concentrated on Perl, rather than giving sketchy coverage of 'Other Tools', it could have been even better (and would have definitely got five starts). That said, the extra coverage (particularly the RegEx engine material) was very interesting and has turned out invaluable in practice. If you are an absolute beginner to Perl or programming you will need another book(s) to get the most out of this one, but it is a gentle and thorough introduction that won't leave you scratching your head, which is a feat in itself considering the complexity of Regular Expressions. This is an excellent book for getting the most out of Perl's RegEx capabilities, you will close the back cover feeling that you genuinely have Mastered the subject. It is without doubt the best book available on the subject, nicely written, with a friendly and un-patronising tone (grammatical errors aside), you can't really go wrong with this one. There could have been some more useful real world examples/projects included, and the book could probably do with an overhaul (it was published in 97) to accommodate Perl 5.6 and other developments (O'Reilly are you listening?), but it is still the best out there. If RegEx is a subject you need to get to grips with, this book is the solution.