DAViCal
DAViCal is an Open-Source CalDAV and CardDAV server.
Setup
If you set up your DAViCal installation to be in your server's root path (i.e. http://[servername]/) CalDAV-Sync and CardDAV-Sync will automatically determine the location of your calendars and address books.
If you have installed DAViCal in some subdirectory (i.e. something like http://[servername]/davical/) the best way to deal with it is to set up a .well-known redirection. Please refer to well-known URLs in the DAViCal Wiki, on how to do that. Just in case you can not set up a well-known redirection, change to manual mode during account creation and enter the base URL of your installation. Both Apps should still be able to auto-detect your resources.
Troubleshooting
If it doesn't sync or you can not set up an account, make sure you didn't change the DAV headers. If you changed them, make sure they contain "addressbook" and "calendar-access". CalDAV-Sync and CardDAV-Sync won't sync if a collection is not advertised as calendar or address book by those headers.