GooCal is the only one I use.
If a program like this one can sync with it by adding features, there's no doubt I would use it.
Right now it would be too much work to start using another calendar app, unless it could sync...
HP , 17.11.2011, 09:15
synchronize my Google Calendar with this.
Falcon, 17.11.2011, 12:40
See it sync with an app on a smartphone like Google calendar does with Android phones.