What You Need to Use This Book

The code in this book was written for PHP5, and it is strongly recommended that you upgrade to PHP5 if you haven't already. That being said, with the exception of the examples using SimpleXML() the code will run under PHP4 (and even in those cases, similar functionality is available from third-party libraries). The examples in this book that require a database use either MySQL or SQLite, so having them available on your test machine would be a good idea (PHP5 includes SQLite in a default install).

Unfortunately, PHP doesn't ship with all of the things required for some of the examples in this book. Appendix C outlines all of the options PHP was built with to develop the code shown within these pages.

Finally, a few of the examples in this book make use of some of the tools that come with the OpenSSL package under Linux to create certificates for authentication purposes. If you do not have access to a machine with this package, you will need to find another way to create these certificates.