new license to review

Seth David Schoen schoen at
Sat May 8 06:31:16 UTC 1999

Tim Pierce writes:

> On Fri, May 07, 1999 at 07:14:40PM -0000, bruce at wrote:
> > > No modifications to Server Identification Field. You agree not
> > > toremove or modify the Server Identification Field contained in the
> > > ResponseHeader as defined in Section 1.6 and 1.7.
> > 
> > I'm concerned about the _precedent_ here, which could be used to enforce a
> > more rigid adherence to some communications protocol or API in _another_
> > _license_.  For that reason, I'd suggest that OSI stay away from this form
> > of license clause.
> Can you be more specific?  What sort of license clause exactly should
> we steer clear of?  In general I think I agree that a license which
> restricts the behavior of derivative works is not really free, but on
> the other hand the GPL does the same thing:
>     c) If the modified program normally reads commands interactively
>     when run, you must cause it, when started running for such
>     interactive use in the most ordinary way, to print or display an
>     announcement including an appropriate copyright notice and a
>     notice that there is no warranty ...
> This requirement doesn't really bother me, but it would be nice if we
> could quantify what kind of restrictions on software behavior are
> permissible in a free software license.

I'd guess that the most concrete point is the absence of any clause in the
new license analogous to "If the modified program normally reads commands
interactively when run".

If you require that a program _must_ display a particular message in a
particular way, you automatically forbid any changes that would make this
requirement meaningless or impossible.  So, for example, I suggested
that this clause means that you can't use code from this web server as
a part of something other than a web server -- because there's no HTTP
response header otherwise.

That really hinders code re-use, and seems to suggest that the original
authors of such code have very narrow expectations about what someone
might actually want to do with the code.  That's fine -- as long as they
don't write it into the license.

If this web server is Open Source, someone who's otherwise willing to
comply with the license shouldn't be prevented from taking useful functions
out of Foobar's code and re-using them in a completely unrelated project.
That project will then be subject to the terms of this license, which is
fine, except that, more than likely, the new program won't be generating
HTTP response headers.

A requirement something like "If the modified program normally generates an
HTTP response header when queried, you must cause it to return or display
as part of such header an announcement including an appropriate copyright
notice" (here just stealing some structure from the GPL -- fair use!) is a
bit more logical, because it says that the program must provide a
copyright/license/credit notice _when appropriate_, leaving open the
possibility that the user could do something to the program such that this
notice no longer made sense in its original form.

Another argument, which is vaguer and perhaps less important, is that
communications protocols are not always considered human-readable, and so
it may be considered bad form to expect human-readable information to be
inserted into them.  (Contrast California Business and Professions Code
17538.45(f)(3)(B), which encourages the practice.)

My main suggestion is that advertising requirements should not be used in
such a way as to burden users and restrict large classes of modifications
or derived works.  There is a danger of that if they are specific to a
particular use of the program.  But I certainly don't know how to resolve
that problem in general.

Foobar will probably get sick of this requirement quickly once someone
deploys some horribly broken alpha-quality patch and some extremely
incorrect behavior is produced by servers calling themselves "Foobar Web
Server". :-)

                    Seth David Schoen <schoen at>
      They said look at the light we're giving you,  /  And the darkness
      that we're saving you from.   -- Dar Williams, "The Great Unknown"  (personal)  (CAF)

More information about the License-discuss mailing list