Add Sogo (Groupware)

README.md

@@ -305,6 +305,7 @@ CMS are a practical way to setup a website with many features. CMS often come wi
   * [Horde](http://www.horde.org/) - The Horde Project is about creating high quality Open Source applications and libraries, based on PHP and the Horde Framework. - `GPL` + Various Free Software / Open Source Software Licenses
   * [Kolab](https://kolab.org/) - Kolab community is a unified communication and collaboration system - `Various FLOSS Licenses` ([Source](http://git.kolab.org/))
   * [ownCloud](https://owncloud.org/) - All-in-one solution for saving and sharing files, photos, music- `AGPLv3` `PHP`
+  * [Sogo](http://www.sogo.nu/) - SOGo offers multiple ways to access the calendaring and messaging data. ([Demo](http://www.sogo.nu/tour/online_demo.html), [Source Code](http://www.sogo.nu/development/source_code.html)) `GPLv1/LGPLv2` `Objective-C`
   * [Tine 2.0org](https://www.tine20.org) - Contacts, Calendar, Tasks, WebDAV, ActiveSync, VOIP, Mail-Client, CRM, Sales, Projects, Timetracker -  ([Demo](https://demo.tine20.net)) - `AGPLv3`
   * [Zimbra Collaboration](https://www.zimbra.com/downloads/) - Email, calendar, collaboration server with web interface and lots of integrations.  ([Source code]( https://www.zimbra.com/open-source)) `GPLv2/CPALv1` `Java`