To celebrate their five years birthday, Packt Publishing offered five books FREE for download. Books include Building Online Communities with phpBB 2, Invision Power Board: A User Guide, Building Websites with e107, and The PEAR Installer Manifesto. Since there is not much books about PEAR, here is one of the few ones available for download free : the PEAR installer manifesto, written by Gregory Beaver, 296 pages and published by Packt on October 30, 2006. The book covers the PEAR Installer version 1.4.0 onwards. Current PEAR stable version is 1.8.1.
pear-installer

This book will show you a new way of organizing your PHP development, by leveraging the full power of the PEAR Installer. In a sense, the PEAR Installer is a step above a software design pattern, a meta-development pattern that can be used to systematically organize all of your PHP development.

You will learn how to organize your code into packages using the package.xml format. You will learn about the revolutionary new PEAR Channel concept, and how to safely and reliably depend on external PHP libraries from sources such as pear.php.net and other PEAR channels. You will learn about the PEAR_PackageFileManager package, and how to customize individual installations of your PHP code through file roles, file tasks, and post-installation scripts.
Update July 8, 2009 : Packt website is encountering some technical issues, we are not able to download also from their website. We notified packt many times about these issues but nothing until today ! There is no need to send us again asking how to download.We’ll update this post when service will be back.