Group-Office

About
Group-Office is a free/open-source groupware package that also has a premium (paid) version with more features. Unlike most web software packages, it is available for repository-based installation for Debian or Ubuntu, allowing for easier installation and maintenance.

Premium Version
Upgrading from free to premium involves installing a license and the Ioncube file, which requires root access (the php.ini file must be modified and PHP will need to be restarted).

Bugs

 * Version 3.5.12 has an email sorting bug.

from Repository
When installed from a repository, Group-Office keeps some information completely outside of the web server files (unlike most web software):
 * /usr/share/groupoffice contains the executable code (mostly PHP, some Javascript)
 * The apt-get installation process creates a link to this folder from a location in the web server file area, rather than just putting the files there.
 * /etc/groupoffice contains configuration files, one of which (config.php) specifies the locations of other key folders:
 * $config['root_path'] ( /home/groupoffice by default) contains some data files
 * $config['file_storage_path'] ( /home/groupoffice/ something by default) specifies the folder where the "file" module stores files
 * $config['local_path'] ( /home/groupoffice/local/ by default): purpose unknown

Links

 * Home page
 * v3.x documentation (runs on MediaWiki with closed registration)
 * Installation: how to set up repository in Debian/Ubuntu
 * v2.x documentation
 * discussion forum