Is CalDAV-Sync Open-Source Software?
Currently it isn't, but it is planned to make it Open-Source once it evolves to version 1.0.
Why don't you make it Open-Source right now?
Because it's not ready yet. Some parts of the source code are quite messy, it would be too embarrassing to publish it ;-)
How do I setup CalDAV-Sync for ...
Please see the list of Supported servers & services then select your server/service to see the set up instructions.
It doesn't sync! What can I do?
My accounts are gone when I reboot the phone!
You've probably moved the app onto the SD card. Android loads all sync adapters during boot. If a sync adapter is not found, a "clean up" method is triggered. This method is important to remove dead accounts when you uninstall a sync adapter. If you move the app to SD then it may not be available during the account check (as the SD card may be mounted at a later time) and your accounts will be removed. So the fix is: Move the app back to the phone.
Only One-Way-Sync seems to work, why didn't it sync the new events to my server?
Please ensure that you choose the right calendar. When you create the event, there is a calendar selection field that may default to your Google calendar. CalDAV-Sync won't sync events in your Google calendar. You can disable the other calendars in your calendar app, so they won't show up in that list (though, I've heard of a few phones still showing disabled/hidden calendars :-/).