CodeIgniter (CI) is a powerful open-source PHP framework with a very small footprint, built for PHP coders who need a simple and elegant toolkit to create full-featured web applications. CodeIgniter is an MVC framework, similar in some ways to the Rails framework for Ruby, and is designed to enable, not overwhelm.
This book explains how to work with CodeIgniter in a clear logical way. It is not a detailed guide to the syntax of CodeIgniter, but makes an ideal complement to the existing online CodeIgniter user guide, helping you grasp the bigger picture and bringing together many ideas to get your application development started as smoothly as possible.
The article continues at http://www.packtpub.com/codeigniter-php-application-development-mvc/book