The configuration script for xntpd is missing. The documentation for xntp in /usr/doc centers around this script. Theres not much info on setting things up manually. I changed the server line in /etc/ntp.conf manually to server clock.psu.edu but that apparently didn't do it. My clock still runs uncorrected. Also note that installing the rpm does not add xntpd to any runlevels. I had to add it manually with the runlevel editor. Bottom line: xntpd doesn't update my clock.
Much of the xntp3 documentation refers to how to configure the build of xntp3. The run-time configuration is controlled by /etc/ntp.conf for which there is a man page. In order to configure the daemon, you will need to identify an xntp server to use. Once that is done, you need to add server your_server_here to /etc/ntp.conf. Provided your clock is within a narrow range (like +- 5 mins) xntp will synchronize your clock to the external server. In order to force initial synchronization, you may also need to put the name of the server you wish to use in /etc/ntp/step-tickers. If that file exists, ntpdate will attempt to set your clock using that server. After 15 mins or so, if your clock is synchronized, the command ntpq -p will show an asterisk after the server currently used for synchronization. The xntp server is not automatically added to any run levels because the majority of our customers have no need of xntp3.