GMP license problem, anyone?

Torbjorn Granlund tg at
Thu May 29 18:42:59 CEST 2008

  I appreciate this question and the openness of discussing it on this
  list. I am working under the assumption that this really originated
  from you and that you wouldn't bring it up unless the matter was
  worrying you.

Eh?  Are you asking me to promise the message was not a fake?  Well, I
can do that, but then this message's validity could also be questioned.

Or what do you mean?

I've read and reread your long posts, but I have not understood the
reasons for your stated problems with v3+.

Have you read the v3 license text, and have a specific problem with
some part of it (which?), or do you have principal objections to the
fact that the license was updated?  In the latter case, one would
solemnly expect you to be using GPL v1.0.  ;-)

  Some months ago now, at a conference, the license issue was brought
  up. Because SAGE makes use of numerous packages, some of which are
  GPL v2+ it cannot change to GPL v3+ and numerous members of the SAGE
  community appear to be against doing that on principal anyway.  I
  have to admit I am also such a person.

Well, what is the principle, spelled out?

  FLINT will always remain GPL v2+ and so cannot ever use future
  versions of GMP if they remain LGLP v3+.

If this is indeed the problem, then it is based on a misunderstanding!
(As other people have already pointed out.)

  I should also point out that the work we are doing on our own version
  of GMP (which I will call X to save typing) and the work I do on
  FLINT, is in many respects insignificant in comparison to the much
  larger businesses which you deal with.

Eh, what businesses?

  At any rate, my point is that the type of sponsorship we are
  attracting (and targetting) is likely to be very different to the sort
  of sponsorship that GMP gets,

If you have managed to get sponsorship for said fork, you're more
financially successful than "the official GMP project" (to use your
words).  The total amount of funding for the last 8 years amounts to
15000 USD.  :-)

  The aims of our new project are also quite different to GMP. Here is a
  list of things we have done or are nearly done doing:


  Anyhow, now that you see what we are doing, back to the licensing
  issue. Clearly FLINT was badly hurt by the license change. It means I
  can't use GMP v4.2.2 or above for FLINT.

Please explain why you "can't" use it.  This is the essence of my

  But is there realistically anything you can do about this? Now that
  you have turned your copyright over the the FSF, can you change the
  license on that code? You don't have control over the licensing any

The FSF, that's us Free Software hackers.

  Obviously I would very much like X to remain fully GMP compatible in
  the future, especially when GMP 5 comes out, since there's some really
  nice stuff going into GMP. But what options do I have? I am going to
  have to redesign and reimplement all that stuff, without looking at
  the code of the people contributing to GMP. And this is open source!?

Seriously, please don't use this sort of rhetoric.  At least not
before you've explained the actual problem.  I suspect the SAGE team's
problem is mere stubbornness, in particular since they have not been
able to produce one single reason form their problems with v3.  But I
am all ears, should somebody spell it out.

I think the forkers over at SAGE use the purported v3 incompatibility
issues as an excuse for forking GMP.  The other publicly stated
reasons are a mixture of blatant falsehoods and sinister insinuations.
This fork exists for some very different reasons than those publicy

  In answer to your other question, yes I am aware of other projects for
  whom the GMP licensing issue, v3+ vs v2.1+ was a problem. But I don't
  wish to speak on their behalf.

I hope you then will apologize me if I don't take this statement very
seriously.  "There are some projects, I will not tell you which ones,
which have some problems, and I won't specify which problems.".

My questions still stands: Does anybody have real, valid problems with
the LGPL v3 which we (the GNU project) could help solve?

The answer "Yes" is not enough, we need you to explain which the
problems are.


More information about the gmp-discuss mailing list