This site uses Jfusion to integrate Joomla and Moodle.

One thing that is great about open source software is the fact that can you do anything you want to it.  I highly recommend that you make as little changes to the core code as possible, however.  The reason is that it makes upgrading to the latest version much trickier.  An easy way to customize your site is by installing add-ons (called extensions in Joomla and plugins in Moodle).  You can install these separately from the core software, and by doing so you are not changing the core code.

Moodle 2.0 is coming soon.  Are you ready?  If not, it's time to start thinking about it.  You will want to upgrade at some point, so now is the time to do some testing.