Affiliate carts are one form of e-commerce where you show products from other shops or catalogs. Visitors to your shop can browse the products on your shop and buy it from that shop or catalog. You don't need to manage the inventory, fulfill the orders, process the payment, and such things. You get the commissions for each sell you generate through your affiliate store. For example, Amazon has a great affiliate scheme which you may be familiar with.

Joomla! has a number of components for adding affiliate shops to your Joomla!-based web site. The following are some of the widely used affiliate shop components for Joomla!:

Paid access to content is another form of e-commerce. If your Joomla!-based site provides premium content for which you want to charge some fees, the following components can help you charge fees to the content, or simply sell access to content:

There are some billing and invoicing system components for Joomla! which are mostly used for managing subscriptions and recurring billing. The following are two such components (commercially licensed) that can be used with Joomla!:

Auction is another form of e-commerce where sellers advertise their products and customers bid for those products. The highest bidder gets the product. Auctions can also be reverse, where a buyer gives his or her requirements and sellers place their bids. In this case, the lowest bidder wins the bid. You can implement such auction systems in a Joomla! site by using some components. The following are two popular components for auction:

There are very few shopping cart components for Joomla! which can truly be an alternative to VirtueMart. The components which can be considered as near-to-be alternative to VirtueMart are mostly commercially licensed. The following are some of them:

As a component of Joomla! and Mambo, VirtueMart is fully integrated with Joomla! and Mambo and shares the common features of Joomla! and Mambo. It uses the security architecture of Joomla! and also has the capability of using Secure Sockets Layer (SSL) encryption, up to 128-bit. This encryption of HTTPS communication makes VirtueMart much safer for the buyers and sellers.

In addition to security features, another good feature of VirtueMart is its flexible tax model. In VirtueMart, sales taxes can be calculated based on a ship-to address, store address, or EU mode. In EU mode, taxes are calculated based on store the owner's address when the customer comes from an EU country.

Customers in VirtueMart are registered users of the Joomla! or Mambo site. Once a customer is registered with Joomla! or Mambo site, that user can maintain their addresses, and also can view their order history and order details.

Whenever a product is sold in VirtueMart shop, an order confirmation email is sent to shopper and the store owner. The administrator of the shop can customize the order confirmation mail and other emails sent to customers.

VirtueMart has excellent localization capability. As part of the Joomla! CMS, you can use multiple languages for the Joomla! site and the VirtueMart shop. Once you install and configure the Joom!Fish component for Joomla!, you can use multiple languages for the VirtueMart store, too. There are several language packs for VirtueMart available on VirtueMart's web site: http://www.virtuemart.net. We can download these free of charge, install the language packs, and use them on our VirtueMart shop. However, if we do not find our desired language pack, we can easily translate the language strings using a Language Translator and Joom!Fish component.

As with multiple languages, we can also use multiple currencies for our VirtueMart shop. When multiple currencies are configured, shoppers can view the product price in configured currencies and also buy using those currencies.

The VirtueMart component can handle thousands of products and categories in its catalog. We can use multiple nested categories to arrange products, and also add products to any category. The entire product catalog is searchable. Shoppers and shop owners both can search the products, categories, and manufactures. We can also filter for discontinued products.

In VirtueMart, the product catalog can be managed through a powerful, web-administration interface. The web interface can use both normal HTML and a JavaScript powered, AJAX-like interface. Like other shopping carts, a VirtueMart product catalog can also be used as a catalog only, where products will only remain for display purposes without displaying prices and Buy Now button. For each product, we can set special attributes and mark any product as special or featured.

Product rating is an excellent feature in VirtueMart. This allows customer ratings on products to be moderated or published automatically without moderation. We can also use a Product is back in Stock feature to notify subscribed customers. VirtueMart can also display how fast a product can be delivered.

In addition to physical products, VirtueMart can handle virtual and downloadable products. Once you configure and upload the downloadable products, customers can view the details of that product, add it to their cart, pay for it, and get it delivered via download.

Administering VirtueMart and catalog configurations is done through its administration panel, which is integrated with the Joomla! and Mambo administration panel. The latest version of VirtueMart has an AJAX integrated interface. The following screenshot shows its AJAX-powered administration panel:

In VirtueMart, we can add multiple images and files for a single product. This gives administrators the opportunity to display multiple product images to demonstrate several product attributes. Similarly, multiple documents may help showing product specifications, technical notes, and so on. The following screenshot shows the product add, edit, and update screen in VirtueMart:

We can add attributes to a product in the VirtueMart catalog. For example, when we are selling a T-shirt, it may have different sizes and colors. Instead of adding multiple products of size and color variations, we may add these as attributes of the product. Once attributes are configured, shoppers can choose appropriate attribute for the product. Some products may be read-only where customers do not have option to select value of that attribute. Product prices can also vary based on the attributes selected.

Another great feature of VirtueMart is adding product type. We can classify our products by product types such as Books, T-shirts, Music Album, Software CD, and so on. For each product type, a set of attributes can be assigned. This makes adding similar products easier.

In VirtueMart, the administrator can create multiple shopper groups, and allow different price levels and payment options for these groups. This is useful for categorizing customers, such as retail customers and bulk purchasers, and assigning special prices for them.

In addition to assigning special prices for different shopper groups, there can be price discounts for certain quantities of an order. Assigning quantity-based pricing helps bulk purchasers. Not only multiple pricing, but the display of prices can be done in different ways. VirtueMart can display prices in different currencies and formats. It may show prices including or excluding taxes. While using multiple currencies for the shop, currencies are converted on the fly using live rates from the European Central Bank (ECB) or some other banks.

In VirtueMart, we can also view some statistics about new customers, new orders, new products added to the catalog, stock levels, and so on. It helps to get an overview of our selling activity. As the administrators can see the stock level for the products, they can help restock the low-quantity items.

The administrative interface also helps in managing orders. The administrative dashboard displays summarys of new orders, orders pending, and so on. From the Orders section, administrators can view more detailed information about orders. They can edit, cancel, or fulfill the orders from this section. While editing or updating any order, an administrator can also notify the customer about the latest status of the order.

The VirtueMart also includes some reporting features. It can display a summary report for old items, and monthly or yearly revenue from the products sold. An administrator can generate these reports by selecting the report type and period of reporting. These reports can show both the summary and individual item statements of products sold and revenue earned.

For any shopping cart, payment modules are essential to process payments online. VirtueMart provides multiple payment processing options with a range of payment modules. It can process credit cards in real time. By default, there are some predefined payment processing gateways such as Authorize.Net, PayPal, 2Checkout, eWay, WorldPay, PayMate, and NoChex. We can also extend our shop to use other payment processing gateways by using the Payment Module API.

A good shopping cart needs multiple shipping modules. These modules help the shop serve its customers better. VirtueMart has multiple shipping modules to serve a wide range of customers. It gives flexibility in adding shipping carriers and rates for the area the store serves. The administrator can configure which carriers they want to use, and at what rate.

Some shipping modules, such as InterShipper, UPS, USPS, FedEx, and Canada Post, can use live update for shipping rates. This helps shop owners to be aligned with the latest shipping rates of the shipping carrier. Some shipping modules can use a shipping rate API. This shipping module API allows administrators to extend the shipping methods.

osCommerce is a popular open-source, PHP-based shopping cart. It has a large number of modules by which you can easily extend its functionalities. osCommerce has some unique features, such as gift certificates, which are not available in VirtueMart. If you are using osCommerce for your shop, and also want to add CMS functionalities by adding Joomla!, you can try integrating osCommerce shop to Joomla!. For bridging osCommerce and Joomla!, there is a component called oscBridge, which can be downloaded from http://tinyurl.com/65l49d.

You can also get an osCommerce-like shopping cart in Joomla! by using ECJC Online Shop (see http://tinyurl.com/2frgx8) and E-commerce solution for Mambo and Joomla web sites (see http://tinyurl.com/59uopt) components.

Zen Cart is another popular open source, PHP, and MySQL-based shopping cart licensed under GPL. It has some advanced features like osCommerce, and provides ease of administration and customization of its look and feel. Zen Cart's powerful features may prelude you to use it with Joomla! to get most powerful CMS and shopping cart hybrid. However, at this point, there is no easy way to integrate Joomla! and Zen Cart. There are some discussions on how to integrate these two powerful open source software. If your shop is not yet running Zen Cart, it is best to build the shop on VirtueMart. If you are running the shop on Zen Cart, you can still migrate your product catalog to Joomla! by using a Joomla! component called the osCommerce Zen Cart Catalog Import Utility. This component allows you to migrate products from both an osCommerce and Zen Cart catalog. You can download it from: http://tinyurl.com/68pwns.

Magento (see http://www.magentocommerce.com) is the newest open source e-commerce project. It is gaining popularity so rapidly that it is assumed, within a few months, it will surpass the popularity of the osCommerce and Zen Cart shopping cart. Magento's popularity is due to its customizability, usability, and extensibility. It is developer-friendly, as well as designer-friendly. Designers can design their shop frontend as they desire. Similarly, with its extensible code framework, developers can customize it and develop new modules easily. However, up to the writing of this book, there is no easy way to use Magento with Joomla!.

Freeway, available at http://www.openfreeway.org/, is another open source shopping cart which can be used for building an independent online shop. If you would like to use Freeway with Joomla!, there is a bridge called Freeway Integration (see http://tinyurl.com/5qmpcx). This component runs on Joomla 1.5.x and integrates the Freeway shopping cart with Joomla! 1.5.x.