I just finished installing Joomla 3.0.3 in MAMP. Initially, I couldn’t get past the environment check: Joomla 3.0 requires PHP 5.3 or higher and PHP must have Magic Quotes GPC Off. Without the correct PHP version and PHP settings, you cannot proceed with the installation.
Note: If you plan to transfer the Joomla 3.0 MAMP site to a web host, you will need the ability to modify your hosting environment to specify PHP 5.3 or higher and the ability to turn off Magic Quotes GPC. If your host does not allow this, then you won’t be able to use Joomla 3.0.
When you install Joomla 3.0, the installation script checks your web environment; if your web environment does not meet the requirements, you cannot proceed with the installation until you modify your web environment to meet the requirements. The most common problems are PHP version and that PHP Magic Quotes GPC is set to off.
There are several methods for fixing the Magic Quote GPC issue.