Where to find documentation to use PERSON_BASIC_SYNC, WORKFORCE_SYNC with third-party

PeopleBooks indicated you can use delivered Sync processes with third party applications.  We are looking into PERSON_BASIC_SYNC, WORKFORCE_SYNC as examples.  Cannot find anywhere who a third party would parse the incoming XML.  Not concerned about how XML gets from PS to third-party.   Just trying to find documenation on what XML actually means and how one would digets its contents.