Horde Groupware

 Horde Groupware is a free, enterprise ready, browser based collaboration
 suite. Users can manage and share calendars, contacts, tasks and notes with
 the standards compliant components from the Horde Project.
 This package is part of Horde, a web application Framework written in PHP with
 modules like IMP (webmail), Turba (contacts), Kronolith (calendar), Nag (task
 list), Gollem (file manager), etc.