The Identity Connector Framework (ICF) has been around since quite some time now (used with OIM 11g R1 +). Oracle IDM has lots of stable connector implementations (using ICF) which are being extensively leveraged in real world IDM deployments e.g. Active Directory, Generic Unix, Generic LDAP, Generic DB-UM, Flat File, IBM Domino Lotus Notes etc.
Here is a quick fire slide share.. just for fun