OpenCart is a traditional competitor and also a highly used alternative to osCommerce. Is easy to install and setup a self hosted online store, it offers many add-ons and graphic templates (designs) to give to your store desired image.
Users can add unlimited number of products, categories and manufacturers, use different currencies and languages, set and display product reviews and ratings, offer various payment options that can be easily integrated.
Also, can manage and process images of your products easily, implement discounts or coupons, print invoices and more.
It displays detailed reports for received orders, products, customers or affiliates that will help you to understand better and have a big picture on your store in order to manage it better.