Commerce.cgi: This version includes the ability to use iTransact or AuthorizeNet for credit card processing. Uses the GNU license.
CommerceSQL: MySQL database driven application for larger merchants with many products.
eButtonz: Application for building online store. Same day setup. Free version has vendor advertisements.
eComPal: Free service available with varying higher monthly cost options also. Works with QuickBooks.
EZ-Powercart: Free application from company offering hosting services and other freebies.
Free Shopping Carts: Perl application with SSL secure server. No limits on number of items. Downloadable zipped file.
Html-Cart: Free html shopping cart program, very easy to install with store manager application. Demo and download available.
Interchange: Open source alternative to commercial commerce servers and application server/component applications.
Mal's Ecommerce: Remotely hosted system that can be built into any existing web site.
VIPcart.com: Same day setup on free service. More advanced features on VIP service that's available for fee.
WebPeddle: Application implented on an existing site. Supports linking to ImagineNation credit card processing service.