Right from the early days of program development, users of osCommerce have developed modifications to the scripts to create extra functionality to that offered by the original code.

These software changes have been packaged into a collection of files (referred to as a contribution) and offered as a download to anyone that wants to integrate them into their osCommerce scripts.

These contributions cover almost every aspect of an osCommerce store, from payment and shipping modules that usually just drop in as an addition, to fundemental changes in how the storeoperates that require substantial PHP editing skills.

These contributions (at least the ones stored in the official osCommerce site) are FREE and have been "contributed" to help others who could benefit from them.

With several thousand available you should be able to find the contributions you need!