WordPress is an online, open source website creation tool written in PHP - probably the easiest and most powerful blogging and website CMS in existence today.
Joomla is an open source platform on which Web sites and applications can be created. Add Universal Chat to your Joomla! website with this plugin.
nopCommerce is an open-source ecommerce based on ASP.NET (MVC). nopCommerce is a fully customizable shopping cart. It's stable and highly usable.
OpenCart is an open-source ecommerce. It is PHP-based, using a MySQL database and HTML components. Support is provided for numerous languages and currencies.
Magento is an open-source e-commerce platform written in PHP. It has well-organized business user tools speed up build up time and enhances productivity.