Hi, Zeuscart is the best opensource ecommerce software for physical as well as digital download products.
Most of them works for digital also but if you are mostly interested in selling digital products then this can help : http://www.goandcheck.com/dlguard-file-download-protection/
I feel Magento is the best, but if you are technically not sound & need a cheap solution for changes in the portal with maximum features then Opencart would be a great choice I believe.
Of course Magento is the best for eCommerce Websites in open source development. It provides many features and one of the best thing is that it is easy to use.
Believe Me Magento is the best platform for ecommerce sites. Magento is flexible easy to use user friendly open source provides many features like ajax Just the best choice for ecommerce websites - ecommerce web developers
You can use Wordpress with WP E-Commerce plugin + few customizations to sell both Physical & Digital goods online. Not only maintaining the cart is simple , but the whole site can be managed through sophisticated WP Admin easily. Hope this helps.
I think few open source good but if you really wanted to run business on eCommerce site then i suggest you that hire one developer who develop eCommerce website using custom PHP & Core PHP... It is more secured then Opensource & CMS... Cheers
i had suggest you to visit www.hotscripts.com and search shopping cart in php > software & scripts section.