jCart is a free Ajax shopping cart that’s easy to install and customize.
Based on jQuery and PHP, jCart handles visitor input without reloading the page and is fully functional even without javascript.

What You Need

• PHP 5.2 or greater
• About 10 minutes to install
• The contents of the cart are sent to jcart-gateway.php before being passed on to PayPal. This file may also be edited to add server side price validation or to use another payment service in place of PayPal.

jCart is created by Doug Whitney under the MIT License. - Converted for Joomla! by Brian Williford

Download Joomla jCart - Or - Download Original jCart

Features

• PayPal checkout integration
• Simple integration with your site
• XHTML compliance
• 2KB of unobtrusive javascript
• Server side input validation
• Easy customization with your text and CSS
• Fully commented code