Setting up CodeIgniter is quick and easy. You can download the version you want from the CI homepage or directly pull the latest version from GitHub. After that, you unzip the contents to the directory that's required. The final step is to edit the
config.php to suit your needs and it's set up and ready for development.
There are also a lot of guides and tutorials from developers who have been using CI for a long time. This is because of the relative old age of the framework and the large community behind it.
CodeIgniter was first released during the times of PHP 4. This means that a lot of features that were added later to PHP are not available. Some of these features are:
- Support for namespaces
- Modular separation by default
- Procedural function helpers
While nowadays CodeIgniter can be used along the latest version of PHP, these features were not added so as not to mess with backward compatibility. They can still be used with CI, but it requires extending core files to make it work which is a waste of time and energy and requires advanced knowloedge of both PHP and CI.