CodeIgniter is an Application Development Framework - a toolkit - for people who build web sites using PHP. Created by EllisLab, fostered by BCIT it is now a project of the CodeIgniter Foundation. The framework implements a modified version of the Model-View-Controller design pattern. Use this tag for questions about CodeIgniter classes, methods, functions, syntax, and use. There are two major versions: 3.x and 4.x, addressing different system requirements