oidentd is an ident (rfc1413 compliant) daemon that runs on Linux, Darwin,
FreeBSD, OpenBSD, NetBSD and Solaris.  oidentd can handle IP masqueraded/NAT
connections on Linux, Darwin, FreeBSD (ipf only), OpenBSD and  NetBSD.
oidentd has a flexible mechanism for specifying ident responses.  Users can
be granted permission to specify their own ident responses.  Responses can be
specified according to host and port pairs.