[ntp:questions] A faster settling NTP

unruh unruh at wormhole.physics.ubc.ca
Wed Dec 23 20:19:03 UTC 2009

On 2009-12-23, Dave Hart <davehart at gmail.com> wrote:
> On Dec 23, 9:16?UTC, David J Taylor wrote:
>> As you hint, a lot of this work has already been done for Windows, both
>> for the slow clock (before Windows Vista) and for the faster-clock (Vista
>> and Windows-7). ?One ?could perhaps ask for permission to borrow that
>> code.
> While that might be nice, my reading of the NTP copyright indicates
> there is no need.  You are free to use the reference implementation
> without additional permission, and with almost no restrictions.  See
> COPYRIGHT in the tarballs, or
> http://www.eecis.udel.edu/~mills/ntp/html/copyright.html
> Some source files have different copyright notices.  My understanding
> is all the programs installed are using similar BSD-style licenses
> which at most impose a requirement to reproduce the copyright notice
> and restrict the use of the copyright holder(s)'s names without
> permission.
> I am not  lawyer and this is not legal advice.  I am however
> interested in reducing the number of different copyright notices in
> the reference implementation.  I'm grateful to Max K?hn and Claas
> Hilbrecht for removing their copyright notices from sntp and
> refclock_neoclock4x, respectively, relying on the overall distribution
> copyright.  The fewer copyright claims and licenses involved, the
> easier it is for third parties to use the code in projects sensitive
> to license issues.  Wasting less time and money on lawyers is a bonus.

The problem is that removing their copyright notice helps not at all,
and in fact makes the situation more complex. copyright is automatic.
They hold the copyright when they make the program. Without an explicit
license, noone has the right to use the program, in the sense that the authors
then have the right to sue for infringement. Now, I suspect they have no
intention of suing anyone, and for private individuals that is enough.
for large companies however, where the suit could reap large dollars,
the companies are not happy to simply rely on the good will of the
writer. So they should either explicitly transfer the copyright to David
Mills, or publish an explicit license. The problem with the current ntpd
"license" is that it is a combination of a copyright claim, and a
license. Thus the writers cannot simply state that they are using the
general license, since it also makes a copyright claim. (It also
confusingly refers to the U Delaware when the copyright holder is D

The license would be better if it clearly stated that each of the
authors (listed in that document COPYRIGHT) releases their work under
the license, and that in addition to the specific claims on parts of the
ntp code he wrote, David Mills claimed copyright in the code as a whole
as a derived work, or something like that. Again this is just for
clarity, since the chances of any of the authors suing is I suspect
vanishingly small. 

Again I am not a lawyer, so if a real copyright lawyer contradicts me,
listen to them, not me, or, if it matters to you, consult one of them. 

> Cheers,
> Dave Hart

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