OpenNTPD is a FREE, easy to use implementation of the Network Time 
Protocol. It provides the ability to sync the local clock to remote 
NTP servers and can act as NTP server itself, redistributing the 
local clock.  OpenNTPD is primarily developed by Henning Brauer as 
part of the OpenBSD Project. The portable version is made by Darren 
Tucker. 

You will need to add the "_ntp" user and group to /etc/passwd and 
/etc/group if it's not present on your system.  Without these groups,
the package will not work.  See http://slackbuilds.org/uid_gid.txt
for uid and gid recommendations.

This package conflicts with the "ntp" package included with Slackware,
so only one of them should be installed at any given time.
The /etc/rc.d/rc.ntpd script in Slackware will not work with OpenNTPD; 
be sure to move the /etc/rc.d/rc.ntpd.new over if you want it to work.