This application is built up around the CodeIgniter framework. CodeIgniter is built directly into the software, so you don't have to do anything extra to use it.
For developers, this framework is freely available on the internet and documentation for using the source code can be founded on their website: http://www.codeigniter.com/user_guide/.
CodeIgniter is a PHP Framework written in MVC (model-view-controller) format which allows developers to create applications that are structured in a very clean and efficient way. When you unzip the product download (core_files/code.zip), you will be presented with the following directory structure. Below is a quick overview of where you can find various files if you are new to using CodeIgniter.
- application - This is where the main application files are kept. It includes the configuaration files, the class controllers, models and view files. If you want to make changes to the application, you should modify these files.
- images - Images used in the application are stored here.
- styles - Custom CSS files made for use with the application.
- system - The core CodeIgniter files are present here. These should not be modified unless upgrading the CodeIgniter version.
- uploads - This folder is used to store user uploads.
- user_guide - Documentation on how to use CodeIgniter.
- .htaccess - This file is used to tell your web server to process URLs.
- index.php - The application bootup file.
You can find more information on directory structure at the CodeIgniter website and reading the User Guide: http://www.codeigniter.com/user_guide/