Perl ( Practical Extraction Report Language) is a general-purpose programming language invented in 1987 by Larry Wall. With over one million users worldwide, it has become the language of choice for World Wide Web development, text processing, Internet services, mail filtering, graphical programming, systems administration, and every other task requiring portable and easily-developed solutions.

As you can see from the title of this book this is the Fourth Edition in a series of programming books from Perl gurus Randal L. Schwartz, Tom Phoenix and brian d foy. The book is aimed at the programmer who does not know Perl but knows the basics of programming, like subroutines, variables and other features commonly found in other programming languages. The book is not a complete reference on Perl, it is for the programmer who needs to know how Perl does the job other languages do.

Given the above, if you are a programmer and you want to "understand" Perl, then this is a great place to start. The book is well organized, easy to follow and the content is well thought out. In my opinion, a thoroughly enjoyable tutorial from cover to cover.

Whats New? Basically the 4th Edition is an update to reflect Perl 5.8. Even though Perl 6 is expected to arrive sometime soon, don't be nervous about buying a book relating to Perl 5.8 because I seriously doubt that Perl 5 will disappear the minute Perl 6 is released. It takes time for people to upgrade to new versions of programming languages and, I feel, this book will be valuable for quite some time.

Wondering about the Llama on the cover? Among Perl programmers, the Perl instruction books are affectionately referred to by the animals on their covers: The Camel book ("Programming Perl"), the Llama book ("Learning Perl"), and a relative newcomer, the Alpaca book ("Learning Perl Objects, References and Modules") ... each animal represents a step on the path to mastery of the language.

So, apart from the 5.8 thing, if you have the 3rd edition of the "Llama" is it worth buying the 4th edition? Absolutely ... the chapters on CGI programming and DBM are gone in the 4th edition ... in their place are chapters on Perl modules and advanced techniques, well worth opening that wallet for. Also, you can use Learning Perl no matter which operating system or environment you are using ... previous versions of the book had a slight bias towards Unix ... the authors suggest they have removed as many traces of that as they could find.

I enjoyed the book, it was easy to read and informative and readily receives space in my personal library. A double thumbs up from me.