How to: Collaborative Software
*Collaborative software or groupware suites.*

* [Citadel/UX](http://www.citadel.org/) - Collaboration suite (messaging and groupware) that is descended from the Citadel family of programs.
* [EGroupware](http://www.egroupware.org/) - Groupware software written in PHP.
* [Horde Groupware](http://www.horde.org/apps/groupware) - PHP based collaborative software suite that includes email, calendars, wikis, time tracking and file management.
* [Kolab](https://www.kolab.org) - Another groupware suite.
* [SOGo](https://www.sogo.nu/) - Collaborative software server with a focus on simplicity and scalability.
* [Zimbra](https://www.zimbra.com/community/) - Collaborative software suite, that includes an email server and web client.