osCommerce, ZenCart, CRELoaded... there are so many Here is my list of opensource e-commerce. * cpCommerce * Opencart * osc2nuke * osCommerce * Zen Cart * Magento * Freeway * OsCSS * CRELoaded * PrestaShop I love osCommerce more.
I'm glad I came across this thread, currently we're supporting three Magento shopping carts and they're all full of bugs, and run very slow on high end dedicated servers. There is no ROI on Magento because you're always paying for developers to fix all the issues. I think we're now going to test Prestashop since it seems to come highly recommended on here. Have you decided on a new eCommerce platform yet? If so, which one?
Magento is a bit slow and difficult in use. But what I like about it that it has a lot of options and can be easily customized. You can add new characteristics, change attribute set etc. Besides with Store Manager for Magento it runs really fast.
Have you considered Znode? They actually have a page here http://www.znode.com//magentoenterprise-alternative.aspx that touches upon a lot of the problems that were expressed related to Magento. I’ve been using Znode for about 6 months and I find it to be a great tool (with virtually no bugs) and a lot easier to use than Magento. The fact that I’ve easily been able to customize my storefront has been a huge deal for me as well (it’s mention on the link that I just posted, but you own and control the source code with Znode).