Re: DRAFT: debian-legal summary of the QPL
Branden Robinson wrote:
>Sounds good. You may or may not want to take into account the Debian Wiki
>page on DFSG-free licenses[1], and what it has to say about the QPL.
I disagree with this to some extent:
> The DFSG-freeness of this license has been called into question. Some
> people appear to believe that because the Qt library is in Debian main,
> that the QPL is DFSG-free. That is a hasty conclusion, however, because
> the Qt library is also licensed under the GNU GPL (see
> http://www.trolltech.com/newsroom/announcements/00000043.html).
As I mentioned on IRC, we shipped QT in main under the QPL before the
GPL was added. I don't think the above is a terribly convincing
argument.
> The QPL is not GPL-compatible, which, regardless of one's opinion about
> the license's DFSG-freeness, poses a major practical problem for any code
> licensed under the QPL that is reused elsewhere in conjunction with code
> under the GNU GPL. This makes the QPL alone a particularly poor choice of
> license for a library.
Indeed.
> Furthermore, it is not clear that the Trolltech corporation (the author
> of the Qt library and the QPL itself) believes the QPL to be a free
> software license. Trolltech's website describes how their dual-license
> approach is intended to be "open source-friendly" (see
> http://www.trolltech.com/company/model.html). If Trolltech felt that the
> QPL alone were friendly enough to open-source, why do they have a
> dual-licensing policy?
1) The FSF list the QPL as a free software license, despite it being in
violation of "You should also have the freedom to make modifications and
use them privately in your own work or play, without even mentioning
that they exist. If you do publish your changes, you should not be
required to notify anyone in particular, or in any particular way."
(from www.fsf.org/philosophy/free-sw.html) - I guess this is an
RFC-style "should". The word "must" is used elsewhere on the page, which
tends to support that.
2) It's arguable that Trolltech did feel that the QPL was friendly
enough in itself. However, while there was argument over the legality of
linking GPLed code against the QPLed QT, there was no real chance of KDE
achieving widespread adoption. This obviously wasn't in Trolltech's
interests.
It's worth remembering that using QT under the GPL is only possible with
GPL compatible code. There is certainly non-GPL compatible code that
uses QT under the QPL. I have no idea if we ship any of it.
> Copyright holders in QPL-licensed works should be encouraged to follow
> Trolltech's example, and dual-license their work under the GNU GPL or
> another clearly DFSG-free license.
I agree. Regardless of whether we consider the QPL free or not, it's
obviously less than ideal.
--
Matthew Garrett | mjg59-chiark.mail.debian.legal@srcf.ucam.org
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