Free contributions vs Paid contributions policy in General Add-Ons Support Posted March 9, 2012 · Edited March 9, 2012 by toyicebear The add-on/contribution is a bridge between oscommerce and their service. The add-on/contribution includes only files and code which is GNU and free. That if you chose to use the add-on/contribution together with their particular service you have to pay to do so does not mater. That falls in the same category as most payment modules, the add-ons/contributions files/code is GNU and free ... BUT if you want to use payment providers/gateways services you will have to pay fees. The files and code included in the add-on/contribution also represents value by themselves in that they can be modified and used for other purposes/services too.