###Multi-websites on single installation of CodeIgniter 2.x.x with shared resources

For the following examples, we'll create two applications:

• 1. a web application
• 2. a mobile application

Both application will share the same resources: models, libraries, helpers.

When you download the distribution and extract the archive, you end up with this layout:

CodeIgniter_2.x.x/
    application/
    system/
    user_guide/
    index.php
    license.txt       

Let's look at my layout for multiple websites:

application/
    web/
        config/
        controllers/
        hooks/
        views/
    mobile/
        config/
        controllers/
        hooks/
        views/
    shared/
        helpers/
        libraries/
        models/
        third_party/
system/
webroot/
    index.php

Models, libraries and helpers are the same for web and mobile applications.

This folder layout lets you store files outside the webroot, primarily for added security. Those files won't be accessible through a web browser, but they will be accessible to your PHP code.