This paper points out and describes the characteristics that are shared between the most of todayâ??s content management systems. The intention was to find what makes the core of todayâ??s content management systems, i.e. what defines them. To provide this, authors analyzed great number of systems on a great number of attributes and features. Systems were compared and analyzed based on their approximate cost, supported operating systems and popularity. The result of those analyses indicates that the most represented and the most appreciated characteristics are support, interoperability with other systems and existence of additional applications that can be integrated into the web site, like blogs, newsletters and guest books