[X4U] Group Scheduling / Calendar Sharing

[Simon Min-Ho Kim]

At our graphic design studio, we are searching for a cross-platform 
solution that allows for group scheduling / calendar sharing. 

We'd like to create one or two calendars, and allow any Mac or Windows 
users to view and edit on any platform on the local network. 

iCal falls short on this department even with .Mac. 

Any other brilliant softwares out there?