osCommerce

I use osCommerce for e-commerce sites and sites that need content management without e-commerce.  Many of the sites in this category do not have ecommerce. osCommerce is ideal for Artist portfolio web sites.

osCommerce is an extremely flexible and powerful plug-in shopping cart catalog, and administration machine all rolled into one. It is open source--and therefore is available for private or commercial use free of charge under the GNU Public Licence, is widely used and supported, and is part of an extremely large online community.  From straight out-of-the-box it looks like a less than exciting gray store-front, but with customization osCommerce can be used to design professional looking web sites with an easy to use administrative back-end interface.