Magento is an ecommerce platform that is a market leader and aimed at mid to larger online stores. It has many features for catalog management, customers, carts and checkout, promotions, and more. There are both free Community and paid Enterprise versions. While sometimes seen as complex or slow, Magento can be successful for smaller businesses too with proper knowledge, training, caching and server configuration. It may be a good choice for businesses serious about online selling that need comprehensive backend and integration capabilities and want a highly scalable solution.