The pidentd package contains identd, which implements the RFC1413 identification server. Identd looks up specific TCP/IP connections and returns either the user name or other information about the process that owns the connection.
-rw-r--r-- 1 root root 1758 jun 7 22:09 /etc/identd.conf -rwxr-xr-x 1 root root 1153 jun 7 22:09 /etc/rc.d/init.d/identd -rwxr-xr-x 1 root root 6164 jun 7 22:09 /usr/sbin/ibench -rwxr-xr-x 1 root root 30744 jun 7 22:09 /usr/sbin/identd lrwxrwxrwx 1 root root 6 jun 7 22:09 /usr/sbin/in.identd -> identd drwxr-xr-x 2 root root 0 jun 7 22:09 /usr/share/doc/pidentd-3.0.16 -rw-r--r-- 1 root root 1235 jan 18 2000 /usr/share/doc/pidentd-3.0.16/BUGS -rw-r--r-- 1 root root 20758 nov 25 2002 /usr/share/doc/pidentd-3.0.16/ChangeLog -rw-r--r-- 1 root root 4365 jan 20 1999 /usr/share/doc/pidentd-3.0.16/FAQ -rw-r--r-- 1 root root 7296 jan 20 1999 /usr/share/doc/pidentd-3.0.16/INSTALL -rw-r--r-- 1 root root 1132 jan 20 1999 /usr/share/doc/pidentd-3.0.16/README -rw-r--r-- 1 root root 270 jan 20 1999 /usr/share/doc/pidentd-3.0.16/Y2K -rw-r--r-- 1 root root 16292 jan 20 1999 /usr/share/doc/pidentd-3.0.16/rfc1413.txt -rw-r--r-- 1 root root 1106 jan 20 1999 /usr/share/doc/pidentd-3.0.16/sgi_irix.txt -rw-r--r-- 1 root root 3621 jun 7 22:09 /usr/share/man/man8/identd.8.bz2