In some ways it is difficult for me to know who should be given credit for the valuable work that made this book possible. It is one of the strengths of the open source movement that good designs and good code take on a life of their own. Aliro, the CMS framework from which all the examples are taken, has benefited from work done by the many skilled developers who built the feature rich Mambo system. Some ideas have been inspired by other contemporary open source systems. And, of course, Aliro includes in their entirety the fruits of some open source projects, as is generally encouraged by the open source principle. My work would not have been possible had it not been able to build on the creations of others. Apart from remarking on those important antecedents, I would also like to thank my wife and family for their forbearance, even if they do sometimes ask whether I will ever get away from a computer screen.