Magento is quite new software (it’s only up to version 1.2.1.2 March 3, 2009) but is already shaping up to be one of the best e-commerce carts out there. Magento features clean urls and SEO from the start. Everything is designed in a clean and simple way. The code it outputs is semantic, which is very rare for e-commerce carts, even commercial ones.

Magento has lots of features and everything is for free. Here is the most important features which you can’t get in lots of others carts.

Management:
You can control multiple websites and stores from one Administration Panel with ability to share as much or as little information as needed. There is Web Services API for easy integration between Magento and any third-party application. If the new version came out you get One-Click Upgrades.

There are Flexible Coupons (pricing rules) with ability to restrict to stores, customer groups, time period, products, and categories. Magento has full international support: Multi-Lingual content, Support for Multiple Currencies.

Checkout:
This cart also has very popular One-Page Checkout and Checkout without account/Guest Checkout. Also it supports shipping to multiple addresses in one order. Also you can view, edit, create and fulfill orders from admin panel. Custommer can re-order from account.

Maggento has over 100 Payment Extensions. The popular ones are: PayPal, Authorize.net, Google Checkout

Products:
There are Batch Import and Export of catalog. Google Base Integration. It supports Downloadable/Digital Products. Layered / Faceted Navigation for filtering of products in Categories and search results. Advanced Pricing Rules and support for Special Prices. You can compare products and review it. You can add multiple images per product and there is a product image zoom-in capability.

This shopping cart is quite popular, so there are lots of templates available on internet for free or to buy. It is good to mention that this cart has iPhone Optimized template too.