1.PrestaShop Shopping Cart Extensions eGrove Systems

2. PrestaShopis an open source e-commerce software solution designed for business firms to carry their sales online. The software is written in PHP and it runs in cross- platform. It is easy to install and customize.
The default PrestaShop installation provides the lot of things needed to maintain a shopping cart web site such as product catalog, stocks, shipping, orders, customers, newsletters, coupon codes, etc managed by the store owner through the administration area.
Also there are more free and commercial add-ons available for adding extra features on ecommerce.
3. Why Prestashop?

PrestaShop is extremely well architected compare to other shopping cart software

4. It is developed using modern software development methods (i.e. Object Oriented with MVC pattern) and because of that we having convenient codebase. 5. It is very easy to customize compare to other shopping cart. 6. It is using advanced functionalities of shopping cart.