I would suggest looking at the K2 extension for managing articles and content.http://getk2.org/index.php
There are also a few other options to view on this page:http://extensions.joomla.org/extensions/clients-a-communities/project-a-task-management
For Community Management JomSocial and Community Builder are good choices as well.
It also depends whether your looking for Commercial or Non Commercial extensions. We don't have any "project management" back end extensions these would all come from a 3rd party.