The web service
If you are after an XML feed for the directory (DSML format) please use this URL:
http://psd.govt.nz/webservice/feed.php?type=dsml&filter=(objectClass%3D*)
As you can see this URL contains two parameters - type and filter. Type can be dsml, ldif, html or csv. The filter is any standard LDAP filter. The abover filter grabs every entry (objectClass=*).
Note: If you are after an XML feed that excludes disestablished organisations, please use this URL:
http://psd.govt.nz/webservice/feed.php?type=dsml&filter=(%26(objectClass%3D*)(!(disestablishmentDate%3D*)))