Drupal is one of most popular open source content management system with high scallable module architecture. Based on modules Drupal can create powerful interactive websites. Basic package system includes modules for blogs, forums, Ecommerce, menu controls etc. Drupal supports a variety of existing themes and allows to create custom themes.
The undoubted advantage of Drupal – complete documentation of the CMS in English.
WordPress is a content management system with open source code, which is easy to install and use. It is widely used for creating websites. Its scope varies from blogs to complex websites. Built-in themes and plugins, which are combined with successful architecture, allow to construct construction any web project on the WordPress base. It is written in PHP and uses using MySQL as a database engine. Source code is licensed according to the GNU General Public License.
Joomla – a universal open content management system for publishing information on the Internet. Suitable for creating small and medium sites and personal pages. Main features include: accounts management, media files management, i18n, advertising campaigns, rating, built-in search, links categorization etc.
Ubercart is a free out-of-the-box software for marketplaces, online stores, auctions, that have been created as ab add-on to the content management system Drupal. Ubercart module can be installed on any server with PHP and MySQL supporting, and is distributed under the GNU GPL license. Ubercart is fully integrated with Drupal. The module can be used to sale goods and services, as well as to download any online products. In addition, it can be used for recruitment and placement, and for the creating of significant events. Ubercart also supports different electronic payment gateways, world currencies and banking systems.
OpenCart – CMS, which is focused on the creation of online shops. Can be installed on any web server that supports PHP and MySQL. Is a free software with the GNU General Public License. OpenCart is built on the principle of MVC, supports multi-shops.