Mauriat Miranda wrote: > On Wed, May 26, 2010 at 5:07 AM, sync <jiannma at gmail.com> wrote: > >> Hello,guys: >> >> I've seen several suggestions for alternatives to exchange for mail, >> which I will be trying. >> >> My question is, does anyone know of any good open source shared calendar >> systems? >> > > I know its not open source, but have you considered Google Apps for > Domains? You can get your own gmail/calendar/docs/sites/chat on your > own domain.com address for up to 50 people for free. As well as > groups/contact sharing/calendar sharing, etc. > > I originally tried it out just for testing, but I find it much > easier/faster than my managing my own hosting. > > I was planning to evaluate devical, but have not tried it yet: http://www.davical.org/ I would welcome comments from anyone with experience with devical. Here's a feature comparison of several calendar implementation, though it looks a little old, based on the versions listed for the various packages. https://wiki.mozilla.org/Calendar:QA_CalDAV_Support I know you asked primarily about calendar servers, but I just thought I'd mention the mailserver that I use. For everything else, I currently run http://www.tummy.com/Products/vpostmaster/ which I like very much. It does not have any kind of calender or contact support, but that can be added seperately. It uses postfix for the underlying mail transport which is very solid and has extensive capability for managing spam attacks and supports many plugins. Vpostmaster implements greylisting, spf checking, spamassasin, clamav, white/black listing. It uses the postgres database. Oh and it also has support for unlimited virtual domains. It includes dovecot pop/imap support and squirrelmail webmail interface. The GUI is quite user friendly and spam control parameters can be customized on a per user/mailbox basis. It's probably most suitable for small to medium size organizations due to the cost of many features implemented in python, though with postfix as the underlying transport, preliminary spam control features, rbl checks, connection rate limiting etc, can easily be implemented at the postfix level. (If a site has big problems with spam attacks, it is desirable to stop them as early as possible, since running lots of python or perl code on huge amounts of spam can bring a server to its knees.) There is already support in the gui to manage parameters which might be read from the database by postfix or a another plugin. A basic install can be done by invoking the installation script on a clean install of CentOS in about 3 minutes. I support about 60 mail users running it in a VMware virtual machine. Nataraj