Am Donnerstag 19 November 2009 schrieb mir Christian Könitzer:
> I installed Lightning in my Mozilla Thunderbird. Lightening supports
> iCalendar (ICS), CalDAV, and Sun Java System Calendar Server (WCAP).
>
> How can I install one of those Servers on my Gentoo Linux (HowTo?,
> Package?)? I searched with eix -S wcap etc. but did nothing found nor
> did I found a server with google. I prefere to instal a WCAP-Server,
> than a iCalendar Server, and if both is not possible a CalDAV-Server...

Different groupwares are available for gentoo, i.e. kolab, opengroupware, 
zarafa.

From zarafa I know it has good support for sync to almost everything 
(thunderbird, outlook, mobile phones but not kontact AFAIK) and a very 
good and responsive web UI but you need for some purposes a license.

Regards
Oli