Under certain circumstances DS Data Systems will sell the entire KonaKart source code, although we prefer to sell an Escrow service where possible.
The Business and Enterprise Editions of KonaKart contain the complete source code of the Client Engine as well as the JSPs and Struts action classes. This gives you full control over the functionality and look and feel of the storefront application.
For the cases where functionality is missing, and it makes sense for this functionality to reside in the KonaKart eCommerce engines, we normally provide fixed price quotes for implementing the missing features and providing an API which we maintain for new releases. This allows you to easily upgrade when new releases become available and also allows you to be supported. The disadvantage of taking the source code and editing it, is that in most cases this results in a branching of the KonaKart code base which becomes difficult to upgrade and maintain.