As someone who has worked with osCommerce for over 12 years, doing installations, custom modifications and so forth, I believe it is safe to say I’m an expert with the project and its code base. It was one of the first open source storefronts and by far more advanced than even some of the ones that came after it for many years. There are hundreds of modules that can be used to extend or change it, too.
Still, I really don’t like it that much.
Forking an open source project is usually deemed to be a really bad thing. Reason being, if you want to make the project better, doing so within the existing code base and working with the original project is the way of making things better for everyone. One big community. In the case of Zen Cart, though, I think it was the right decision. Zen Cart is a fork of osCommerce and where osCommerce fails, it succeeds.
While I think osCommece was ground breaking and clearly an excellent example of an open source success, the UI never got very far; it always looked like a developer designed it. The speed with which updates rolled out was terminally slow — after more than a decade, we’re still only on version 2.2? Zen Cart on the other hand took seriously the design and presentation aspects of the program. They also made the directions better and with greater usabilty for both developers and novice users alike. The standard installation for Zen Cart includes most of the features I spend a great deal of time adding to any osCommerce standard installation. As such, an installation of Zen Cart gets me further and is easier to manage and maintain.
For me, Zen Cart is a better project and a better solution for most people when it comes to an open source ecommerce platform.