CodeIgniter 4 is the upcoming version of CodeIgniter. CodeIgniter is a popular and powerful MVC (Model-View-Controller) framework that is used to develop web applications. It is a free and Open-source PHP framework.
Before you proceed you should have a basic understanding of the following:
CodeIgniter was created by EllisLab and is now a project of the British Columbia Institute of Technology.
The latest version of the CodeIgniter framework is 4.0.4.
The source code of CodeIgniter is hosted on GitHub and licensed under the terms of MIT License.
As it is open-source software, you are allowed to copy, modify, and distribute this software.