Tip

This is the documentation for the 19.12 version. Looking for the documentation of the latest version? Have a look here.

NTP License

The ntp.org NTP daemon uses a custom open source license known as the NTP License.

A copy of the NTP License template is found at https://opensource.org/licenses/NTP .

The full text of the license as used by NTP is included below.

The following copyright notice applies to all files collectively called the
Network Time Protocol Version 4 Distribution. Unless specifically declared
otherwise in an individual file, this entire notice applies as if the text was
explicitly included in the file.

***********************************************************************
*                                                                     *
* Copyright (c) University of Delaware 1992-2015                      *
*                                                                     *
* Permission to use, copy, modify, and distribute this software and   *
* its documentation for any purpose with or without fee is hereby     *
* granted, provided that the above copyright notice appears in all    *
* copies and that both the copyright notice and this permission       *
* notice appear in supporting documentation, and that the name        *
* University of Delaware not be used in advertising or publicity      *
* pertaining to distribution of the software without specific,        *
* written prior permission. The University of Delaware makes no       *
* representations about the suitability this software for any         *
* purpose. It is provided "as is" without express or implied          *
* warranty.                                                           *
*                                                                     *
***********************************************************************

Content starting in 2011 from Harlan Stenn, Danny Mayer, and Martin Burnicki is:

***********************************************************************
*                                                                     *
* Copyright (c) Network Time Foundation 2011-2015                     *
*                                                                     *
* All Rights Reserved                                                 *
*                                                                     *
* Redistribution and use in source and binary forms, with or without  *
* modification, are permitted provided that the following conditions  *
* are met:                                                            *
* 1. Redistributions of source code must retain the above copyright   *
*    notice, this list of conditions and the following disclaimer.    *
* 2. Redistributions in binary form must reproduce the above          *
*    copyright notice, this list of conditions and the following      *
*    disclaimer in the documentation and/or other materials provided  *
*    with the distribution.                                           *
*                                                                     *
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS  *
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED   *
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE  *
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE    *
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR *
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT   *
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR  *
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF          *
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT           *
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE   *
* USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH    *
* DAMAGE.                                                             *
***********************************************************************