Open Atrium – Beautiful Drupal-Based Intranet cum do-it-yourself project
Open Atrium is a open source multilingual web application to create Drupal-Based Intranet, where teams and co-workers can easily collaborate.
Open Atrium is highly customizable and extensible, it means that any one can developed the new features, add other modules and easily customize the interface of Open Atrium as per there teams requirements and do anything else that you can think up to make Open Atrium meet your exact needs.
It is built on the Drupal framework & has modules like a blog, a wiki, a calendar, a to do list, a shout box, and a dashboard to manage it all.
Open Atrium is easy to Install, you need PHP 5.2, PHP GD extension and use MySQL 5 for database. it also use Apache
mod_rewrite module for create clean urls and supports the major standards-compliant browsers like; Firefox 2+ , Safari 3+, Internet Explorer 7+.