Re: Revised LaTeX Project Public License (LPPL)

[Walter Landry <wlandry@ucsd.edu>]

Jeff Licquia <licquia@debian.org> wrote:
> On Sat, 2003-04-05 at 00:44, Walter Landry wrote:
> > Jeff Licquia <licquia@debian.org> wrote:
> > > So you do not acknowledge that a particular license might contain
> > > elements that are specific to the problem domain?
> > 
> > Of course I don't acknowledge that.  One of the wonderful things about
> > free software is that you can apply it to other problem domains.  To
> > limit the problem domain is to restrict modifications.
> 
> "elements specific to the problem domain" != "limit the problem domain"
> 
> For example:
> 
> "If the modified program normally reads commands interactively when run,
> you must..."
> 
> (GPL, 2c.)
> 
> Is this a restriction that GPLed code must read commands interactively
> when run?  No, of course not.

I see what you're saying.  We allow people to place certain
restrictions and still have a free license.  Those restrictions can
selectively applied to certain problem domains.  But those are
restrictions that we allow in all domains.  So, in a sense, the
license is selectively lifting restrictions in certain domains, which
is always ok.

<snip>
> > > This example seems to indicate that your main problem with the
> > > validator is that it seems like a programmatic restriction.  If it
> > > were made more clear that this is not the case, would this satisfy
> > > you?  How would you change it?
> > 
> > It would satisfy me, but I can't think of a wording that will likely
> > satisfy the LaTeX people.  The only place where you can really say
> > that something is only for people, and not for machines, is in
> > something that machines don't read (e.g. comments).  Beyond that, you
> > get into things that aren't really part of the program (e.g. don't
> > call the "thing" LaTeX).
> 
> This is not true in at least one case: copyright notices.  We already
> allow the GPL to require the printing of copyright notices when run
> under certain circumstances.  If the mechanism I mention is a mechanism
> for the printing of copyright notices on the code, then this restriction
> is no more onerous than the restriction in the GPL, as I see it.

Fair enough.  GPL 2c talks about running commands interactively, and
that is also strictly for humans.

> And, having worked with the LaTeX people for a while now, I think it's
> fairly likely that they'll accept wording to that effect.

The reason I was pessimistic is because the individual files are not
interactive programs.  They are interpreted by another program.  That
program could easily change it's behavior based on what it reads.  If,
for example, I created a "Trusted LaTeX" that aborted if the
validation didn't work, then not allowing people to make modified
versions that work in trusted LaTeX is too much of a restriction.

But this also touches on one thing that Frank said.  He seemed to
imply that it doesn't actually matter what program you're using, the
Base Format is just the format defined by LaTeX.  So if the LaTeX
people become evil and later decide to change the format so that you
get different behavior with non-validating files, then there has been
a retroactive change in the licensing terms.  What exactly the format
is needs to be nailed down.

Regards,
Walter Landry
wlandry@ucsd.edu