The following list of open source Ecommerce development tools and platforms is provided for your convenience and should not be viewed as an endorsement of any particular product. All product descriptions were provided by the software companies.
Magento Community Edition, Magento, Inc., US
The Magento Community Edition is available as a free download under the open source OSL 3.0 license and is recommended for expert developers and highly technical enthusiasts and hobbyists in non-mission critical environments. As this edition is unsupported it is intended to be used by those happy to spend time and resource solving issues independently.
Liquid, Jaded Pixel Technologies, Inc., Canada
Liquid is a Ruby Library for rendering safe templates which cannot affect the security of the server fhey are rendered on. As an extraction from the e-commerce system Shopify, it allows customers to have complete design freedom while maintaining the integrity of the server. Liquid has been in production since June 2006 and is now used by many other hosted web applications. It was developed for usage in Ruby on Rails web applications and integrates seamlessly as a plugin, but also works excellently as a standalone library.