OpenCart

OpenCart is a free, open-source shopping cart solution known for its lightweight core and straightforward administration panel. It has a large marketplace of extensions and themes to add functionality. Its appeal lies in its simplicity for developers to set up and customize for small to medium-sized projects. However, the core codebase is considered legacy by modern standards, and the quality of third-party extensions can be inconsistent.

Like all self-hosted platforms, users are responsible for security, hosting, and updates. It's a viable low-budget option for technically adept users or developers who need a simple, customizable storefront without the bloat of larger systems.