osCommerce is an extremely flexible and powerful plug-in shopping cart, catalog, and administration machine all rolled into one. It is open source--and therefore is available for private or commercial use free of charge under the GNU Public Licence, is widely used and supported, and is part of an extremely large online community. It consists of a catalogue front-end, which can be used in conjunction with your existing site, or as a stand-alone site in its own right; and an extremely easy to use administrative back-end interface.

It is available right now for download from www.oscommerce.com as a .zip package weighing in at just under 1.5Mb. Also featured on the site is the showcase section with links leading to sites implementing osCommerce, and the community services mini-site containing the forums and documentation.

The application is PHP based and connects to an SQL database, so your hosting vendor must provide compatible services. It also contains a little JavaScript and a lot of HTML, and is available for either Windows or Linux platforms.

There is no doubt that osCommerce is an excellent solution for anyone looking to implement an online store with the minimum of expense and hassle; it is ready to go almost immediately after installation. All you need to do is add your products using the back-end administration tool, and add some of your store's personal information (such its business address, policies and delivery details). If you’re happy with the layout and color scheme, that’s almost it. Go live, make money.

But what if you’re not happy with how it looks? Or want to add or remove certain features? The community services are there of course, but why read through countless online documents, or start a thread in the forum and hope that someone replies? This article will outline some of the basic changes that need to be made in order to customize the catalogue and shopping cart.