On 6 Mar, 13:15, David Harvey <dmhar...@cims.nyu.edu> wrote:
> On Mar 5, 10:28 pm, Bill Hart <goodwillh...@googlemail.com> wrote:
>
> > Let's clear up another misconception here. GPL v3+ software is NOT
> > banned from Sage. This is explicitly stated online.
>
> Where does it say this?
It's actually been stated a number of times in threads on this list.
In the last few days it was reiterated that the Windows port will
*allow* GPL v3+ software.
Probably there is a little bit of confusion between two issues:
* The Windows port of Sage - which MSR is paying for
* The MSR special release of Sage - which will be GPL v2+
They are totally separate. Thus there is no restriction on GPL v3
stuff in even the Windows port, let alone the other versions of Sage.
But that's ok. It is just a matter of getting the word out, which
hopefully this thread will help with.
> The comments on this thread suggest that Sage
> will not upgrade to the next release of MPFR solely because of the
> license change, which suggests that a de facto ban on GPL3 code is in
> place.
That may appear to be the implication, but it isn't. It just makes it
more difficult for the people putting together the MSR GPL v2+
version.
>
> > It just doesn't get included in the GPL v2+ version of Sage,
>
> What do you mean, "GPL v2+ version of Sage"? Where can I download this
> version?
If it were that easy, we'd already have a link for you. At present,
all I can say is if you download all the GPL v2+ pieces and none of
the GPL v3+ pieces, you have the GPL v2+ version of Sage. If it
doesn't compile for you, please send a patch.
It's an ongoing effort. Significant progress has been made!
Fortunately only a handful of projects have switched licenses, making
this work less troublesome. Some GNU projects and that is about it as
far as I can tell.
> As far as I know, there is only one Sage download available,
> and it does not include any GPL3 code.
>
That hasn't been true for quite a while, well not if you mean to
include LGPL v3. GMP went LGPL v3 when it was still in Sage. There are
other packages in Sage (which won't be in the GPL v2+ version) which
are (L)GPL v3+.
My point was not that Sage won't distribute GPLv3+ software, but that
it is unfortunate if open source mathematical projects are switching
to GPL v3+ purely because of misinformation.
Somehow there is the perception that GPL v3+ is a magic bullet against
being sued by Microsoft. "We've got protection, double crossed, no
returns, nyah, nyah". The misinformation is that GPL v3+ contains
clauses to penalise patent aggression and that the GPL v2+ does not.
So the perception is that if we license our code GPL v3+ it keeps us
safe from the raving monster.
Actually, some of the patent clauses that were going to be added to v3
were scrapped before the final draft. What remains is section 11 of
GPL v3 which basically says that if a contributor gives you code and
they have patents related to it, they don't take away any of the free
software rights you would have had otherwise, from the contribution.
In patent language they grant you a royalty free patent license. It
then has some specifics about extending that license to downstream
recipients, etc. Finally it restricts deals with software companies
who want you to distribute software with a discriminatory patent (one
which prevents you from fulfilling the requirements of the GPL). And
specifically it looks like *you* have to be paying money *to* that
software company in order to fall afoul of that restriction.
*But* section 7 of the GPL v2 already dealt with patent issues and
essentially says that in the case of a patent conflict with the terms
of the license, you have to stop distributing the software. It
explicitly says that you cannot use a patent issue to excuse you from
your obligations with regard to the license, the intention being to
*protect the integrity of the free software distribution system*.
As you can see from reading both, neither gives you protection if you
choose to distribute software which violates someone's patent. You
can't distribute software under the GPL under those conditions. One
also sees that both versions of the license are clear about situations
like the MS vs TomTom one. *IF* MS's patent claims are upheld, it
makes no difference which version of the license is used, TomTom will
have to stop distribution under the GPL. It's ironic that TomTom is
not even an open source software company, but a proprietary GPS
hardware navigation company. The whole TomTom issue is irrelevant to
Open Source mathematics.
The other thing which is important to note is that a recent court case
in the US set a precedent that software patents are only enforceable
when associated with a specific device (a general computer not being
applicable). Thus MS could not go after an open source software
project as such, but could potentially go after a hardware company who
is using open source software as a system for accomplishing something
which MS have a patent covering. As I mentioned, neither version of
the GPL gives you protection if MS can prove that your device
infringes their patent.
MS have also said they do not intend to go after open source software
companies. Again, note that TomTom is not an Open Source software
company.
It simply doesn't make sense to me to switch licenses, believing that
somehow v3 extends to me some new protections as a software author or
maintainer of a package, from MS and its patent lawyers. It makes even
less sense to suppose that somehow this issue has any relevance to
those of us writing open source mathematics. The only thing switching
to GPL v3+ will do is retaliate against MS by preventing MSR employees
from running it (which is quite misdirected retaliation IMHO, as those
folks have actually done a lot to support open source mathematics, and
have nothing at all to do with the MS "corporate monster"'s
behaviour). And the other thing it will do is make life more difficult
for those of us working on a GPL v2+ only version of Sage for our
friends at MSR.
Please consider carefully before taking any decision to switch.
I didn't see any discussion of this issue on the MPFR list. Perhaps
they decided to forego a public discussion because of an inevitable
flame war. But either way, it is unfortunate that they made the
decision which they made, and even more unfortunate that the reasons
given don't stack up.
In the post which Alex made, which quotes Paul Zimmermann, MPFR is
referred to as a GNU project. I was unaware that it was a GNU project,
and I don't find this information on their website. However, given
that this is the state of affairs, I could imagine pressure from the
FSF to license using LGPL v3+. I realise I don't know the reason
behind it. But I do wonder if a campaign of misinformation about v3
has gripped a few too many people.
Bill.
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