Projects
DAVdroid integrates CalDAV/CardDAV into Android! GPLv3, available in various stores.
More than 20,000 licenses sold. Winner of the Constantinus Award 2014 (category: open-source).
ICSdroid synchronizes external calendars (.ics/iCalendar) with your Android device in regular intervals.
Typical use case: school/university/club calendar
Community related to the free image manipulation software GIMP, featuring tutorials, news, forums, polls and contests.
Various open-source projects and contributions, e.g. CAdroid, GfxTablet, TeamSpeak3 port for FreeBSD, countless bug reports and patches, especially for Android, CalDAV/CardDAV servers etc.
Video trainings for Rheinwerk Verlag, book: CSS pur (Pearson Education/Addison Wesley)
