https://oscmax.com/wp/

osCmax is a powerful e-commerce/shopping cart web application. osCmax has all the features needed to run a successful internet store and can be customized to whatever configuration you need.

https://www.opencart.com/

OpenCart is shopping cart solution. You simply install, add products and you're ready to start accepting orders. It has order management and multiple payment gateways already built in.

https://onxshop.com/

Easy web CMS/eCommerce Onxshop is an elegant solution discovering underlaying principle of web content management.

http://mymarket.sourceforge.net/

MyMarket is a fully functional online shopping catalog system, built using PHP and MySQL. It was created by Ying Zhang for the purpose of teaching people about the basics of creating an E-Commerce site.

https://magento.com/

https://www.cubecart.com/

CubeCart is an eCommerce script written with PHP & MySQL. With CubeCart you can setup a powerful online store as long as you have hosting supporting PHP and one MySQL database.

https://www.alegrocart.com/

AlegroCart is based on MVC design, support for all Countries, Zones, and Geo zones. It has many modules: HomePage, Image Display, Fancybox, Checkout, SSL support, Captcha, etc.

http://websiteatschool.eu/

Website@School is an Open Source Content Management System (CMS) specially designed to both learn and build websites for schools. It has special features for blind and visually impaired users and webmasters.

https://pkp.sfu.ca/ojs/

Open Journal Systems (OJS) is a journal management and publishing system that has been developed by the Public Knowledge Project through its federally funded efforts to expand and improve access to research.

https://pkp.sfu.ca/ocs/

Open Conference Systems (OCS) is a free Web publishing tool that will create a complete Web presence for your scholarly conference.