How does Plone compare with Sharepoint, Drupal, Alfresco and Joomla?
Plone is a true CMS with built-in publication workflow and document management features, unlike other systems such as Sharepoint or Alfresco, which are primarily document management systems with limited web functionality. This makes Plone ideal for intranets and extranets.
Plone can be customized and extended to meet the specific needs of an organization in terms of site structure, content types, workflow rules, etc. Not all CMSes offer the same level of flexibility.
Because it is built on top of Python and Zope, Plone is very secure, which is a reason why many switch from Joomla and Drupal to Plone.
Plone is 100% open source, so released, stable versions can be downloaded for free. There’s no need to purchase a per-server or per-user license to get commercial support, as is the case with Alfresco or Sharepoint.