We can find in the market:

• Web Content management platforms (like Joomla), usually called "Content Management Systems" , will be referred here as CMS
• Conferencing tools (like webex, MS Live meeting)
• Learning management tools (like moodle) , additional common names are  "Learning Management Systems"  (LMS) or "Learning Content Management Systems" (LCMS) or "Course Management Systems" (CMS, confusing term with the CMS from above).  We will refer them here as LMS.
• Social platforms. (like facebook).

What they usually do and what they lack:

In each category of the above, there are dozens of applications in the markets. In this document we will mention the major or best players in the markets, and we will base our examples on those who are considered "top of the line" or have largest market share.

Common features found in  CMS  may be:

1. Automated templates
   Create standard output templates (usually HTML and XML) that can be automatically applied to new and existing content, allowing the appearance of all of that content to be changed from one central place.
2. Easily editable content
   Once content is separated from the visual presentation of a site, it usually becomes much easier and quicker to edit and manipulate. Most WCMS software includes WYSIWYG editing tools allowing non-technical individuals to create and edit content.
3. Scalable feature sets
   Most WCMS software includes plug-ins or modules that can be easily installed to extend an existing site's functionality.
4. Web standards upgrades
   Active WCMS software usually receives regular updates that include new feature sets and keep the system up to current web standards.
5. Workflow management
   Workflow is the process of creating cycles of sequential and parallel tasks that must be accomplished in the CMS. For example, a content creator can submit a story, but it is not published until the copy editor cleans it up and the editor-in-chief approves it.
6. Document management
   CMS software may provide a means of managing the life cycle of a document from initial creation time, through revisions, publication, archive, and document destruction.
7. Content virtualization
   CMS software may provide a means of allowing each user to work within a virtual copy of the entire Web site, document set, and/or code base. This enables changes to multiple interdependent resources to be viewed and/or executed in-context prior to submission.

Real world examples