Introduction to the CodeIgniter PHP Framework

Building web applications with PHP is a pretty simple process. As a PHP developer, you can develop practically anything, including database abstraction layers, form validation programs, file upload applications, and so forth. The list goes on and on.
Once you've mastered the foundations of the object-oriented paradigm and learned how to implement certain common design patterns in real-world conditions, you should be armed with a useful toolkit comprised of all sorts of classes and functions that can be used any number of times.
Although you may not be aware of this fact, your toolkit can be considered a general PHP development framework. The end result of your own efforts and skills as programmer.
However, there are certain situations when the capabilities offered by your own framework simply aren’t good enough to fit the requirements of a particular application. In a case like this, you can either upgrade your framework, which will probably require coding additional classes and functions, or you can pick up a third-party software from the numerous packages available on the web today.
If you choose the latter, then you’ll be confronted with another challenge that will keep your mind spinning in circles. Should I pick up a full-featured framework like Zend, or should I work with a more approachable solution, like CakePHP or WACT?
Actually, the answer to that question depends strongly on what type of project you’re going to develop and how much time you want to spend configuring and learning how to use a particular framework. For instance, Zend is great for building enterprise-level PHP applications, but it's likely that you’ll find it pretty overwhelming to work with at first.
On the other hand, CakePHP can be much easier to set up and use, even though they’re not loaded with all the features offered by Zend. However, in the last few months, a small framework has gained popularity with many PHP programmers due to its ultra-fast learning curve and easy configuration.
Actually, I’m talking about CodeIgniter (http://codeigniter.com), a solid piece of software written by Rick Ellis in PHP 4. It permits users to develop small and middle-scale PHP applications in minutes (literally) with minimal setup. In addition, CodeIgniter is built around the Model-View-Controller pattern, which allows you to easily separate data from application logic and visual presentation.