Out of the box, CodeIgniter only supports MVC. This tutorial explains how to add HMVC to CodeIgniter by installing BackendPro 0.6.1 into a Multi-Site CodeIgniter 1.7.2 installation for some nice, modular goodness.
CodeIgniter is an incredibly powerful and easy to use PHP Framework that makes developers’ lives alot easier. In its default configuration it only supports one site per installation – quickly result in thousands of files on your file server which can be a pain for all involved. With a little fiddling we can fix this.