The following are links to some demo installations of a number of different open source PHP / MySQL software programs including Joomla, WordPress, Zen Cart, and Drupal. To see of a demo of admin area for each of the installations below, use "demo" for both the login and password).

Joomla     Admin Demo
Joomla 1.5     Admin Demo
Drupal 6.1     Admin Demo

Zen Cart     Admin Demo

Wordpress     Admin Demo
Wordpress 2.5     Admin Demo
Nucleus 3.32    Admin Demo
b2evolution 1.10.2    Admin Demo
Mambo version 4.6.3    Admin Demo
MODx version 0.9.6.1    Admin Demo  (Use "admin" for login ID)
Magento version 1.0.19870.2    Admin Demo (Use "demodemo" for the password)
PunBB version 1.2.17    Admin Demo (Use "admin" for the Log in ID)

osCommerce version 2.2 rc2a    Admin Demo
CubeCart version 3.0.17    Admin Demo
Moodle version 1.9    Admin Demo