Magento: Magento is a widely-used open-source ecommerce platform that is known for its flexibility and scalability. It offers a wide range of features and can be easily customized to meet the needs of different businesses.

WooCommerce: WooCommerce is a free WordPress plugin that can be used to create an online store. It is popular among small and medium-sized businesses and is known for its simplicity and ease of use.

OpenCart: OpenCart is another free open-source ecommerce platform that is easy to set up and use. It offers a range of features and can be easily customized to suit the needs of different businesses.

PrestaShop: PrestaShop is an open-source ecommerce platform that is known for its ease of use and user-friendly interface. It offers a range of features that can help small and medium-sized businesses sell their products online.

osCommerce: osCommerce is a widely-used, open-source ecommerce platform that offers a range of features and can be easily customized to meet the needs of different businesses. It is widely supported and has a large community of developers who contribute to its development and maintenance.

Spree Commerce: Spree Commerce is an open-source e-commerce platform for Ruby on Rails developers. It is flexible, extensible and customizable, also includes a lot of features out of the box and backed by a large and active community.