The NTP Project
The NTP Project produces a reference implementation of the NTP protocol, and implementation documentation, through a largely a volunteer effort. The NTP software distribution is copyrighted, as described in the
NTP copyright page.
A list of reference clocks, ntp documentation, time and frequency standard stations, and time and frequency standard station transmission data is maintained at the
Information on Time and Frequency Services page. Background information about NTP, along with briefings and a bibliography, are available at the
Network Time Synchronization Project page.