Arcavias is an e-commerce framework for Web shops, consisting of an e-commerce library, an administration interface, and different frontends. It's a modular stack which offers flexibility and speed. Unlike other Web shops, it's not a monolithic application. Instead, you have a choice between several user frontends, and you can adapt them to your needs or write one of your own.
Saint CMS is a combination CMS and eCommerce package built atop a rapid development framework. It is high performance, easy to use, and provides convenient tools for creating sites with custom content types. It includes a built-in blog, an image gallery, a slideshow, a file manager, a shop with downloadable product options, an event logging system, a WYSIWYG editor, and more.
Window Shopper for Firefox allows you to instantly compare prices on any product on 3,200 U.S. online stores, including Amazon and eBay. If it finds a deal, it will show it. Otherwise, it will show you similar products you may also be interested in. After you install Window Shopper, you will see a "See Similar" icon appear next to product images. Just click on the icon and the Window Shopper window will appear, presenting deals and visually similar products from hundreds of online stores.