SOGo

by @github

SOGo offers multiple ways to access the calendaring and messaging data. CalDAV, CardDAV, GroupDAV, as well as ActiveSync, including native Outlook compatibility and Web interface. ([Demo](https://demo.sogo.nu/SOGo/), [Source Code](https://github.com/Alinto/sogo)) `LGPL-2.1` `Objective-C`