In general, you can use any WebDAV compliant Content Management System (CMS) as long as it is at compliance level 2. Commonly used systems are the Knowledge Management of the SAP Portal, the Apache (with mod_dav) and the IIS.
The SAP Authoring uses WebDAV to publish elearning content.
In order to check whether your CMS in the current configuration is suitable for you can run the Function Test of the standalone Repository Explorer via Tools->Function Test.
The only supported authentication mechanism is Basic Authentication.
The Authors need read/write access to the repository whereras the systemuser of the Content Player needs only read access.
In order you have any problems with checkin please check the SAP note 914824 "FAQ Authoring Environment- SAP Learning Solution".