X-cart is King

X-cart is a very mature web development platform for e-commerce stores. Its well tested and battle-hardened over more than a decade of development from one of the best software teams on the planet.

I have been working with XC for almost 7 years now, and I have yet to find a better backbone for your e-commerce site. It is a developer's platform, you can create almost anything you can imagine, since it's open source nature gives you, or your dev, full access to the code.

All the features you could ask for. And the features have been tweaked and added to from real world merchant experiences. It's not likely that you will need to do something that XC doesn't already do. :-)

If you want to build a mature, competitive website, than X-cart has everything you need in a nice tidy package. The price simply can't be beat, and purchase gives you unlimited lifetime access to upgrades. You won't get that anywhere else.