Semi-widely used I'd say. XMPP and SIP come to mind... What I like about DNS SRV is that it's standardized and relatively simple to handle, in contrast to some

Semi-widely used I'd say. XMPP and SIP come to mind... What I like about DNS SRV is that it's standardized and relatively simple to handle, in contrast to some of the other naming schemes out there (eg. CORBA). I agree though that tools / libraries need to get better here.