We recommend osCommerce for businesses wanting to develop highly custom eCommerce sites.
In our experience, osCommerce has the lowest cost of ownership of any open source solution and therefore is cost-effective when it comes to offering a unique online eCommerce solution.
Originally the community edition of osCommerce 2.3, Phoenix Cart has become its own entity. We applaud their intention to improve the code from a technical perspective while keeping the UX the same and the code base lean and fast eCommerce solution.
Although there are several WordPress eCommerce Plugins available, we recommend WooCommerce as solution for startups or small businesses that have a small product catalog where they have a story to tell before they sell.
Please note we’ve done Woo Sites with very large catalogs too!