There are many features that are listed on the websites of the Companies that create scripts. Don`t get fooled, only 4 are important!
Ease of use
Joomla is an award-winning content management system (CMS), which enables you to build Web sites and powerful online applications. Many aspects, including its ease-of-use and extensibility, have made Joomla the most popular Web site software available. Best of all, Joomla is an open source solution that is freely available to everyone.
WordPress is a state-of-the-art publishing platform with a focus on aesthetics, web standards, and usability. WordPress is both free and priceless at the same time. More simply, WordPress is what you use when you want to work with your blogging software, not fight it.
Drupal is an open-source platform and content management system for building dynamic web sites offering a broad range of features and services including user administration, publishing workflow, discussion capabilities, news aggregation, metadata functionalities using controlled vocabularies and XML publishing for content sharing purposes.
Pimcore is a powerful and robust Zend Framework based PHP content management system (WCMS) for creating and managing digital content and assets. Besides being a full-featured open-source WCMS system, pimcore is the first and premier PHP open source enterprise product information management framework (PIM) available.