3rd parties can submit items via the SWORD interface. For example ETD's could be submitted via the campus student information system directly to the repository after a campus senate approved digital workflow.
3rd parties can harvest from the repository using the OAI-PMH interface. For example the repository could be harvested by your local research office for reporting or by your national research foundation.
http://wiki.lib.sun.ac.za/index.php/SUNScholar/OAI-PMH and https://wiki.duraspace.org/display/DSDOC18/OAI
3rd parties can receive alerts via the RSS/Atom interface.