6 ms·

Adding LGPL v3 to Qt

74 points by Tsiolkovsky 12y ago

pkorzeniewski 12y ago
If you have no idea (like me) what's the difference between LGPLv2 and LGPLv3 and what are the implications, here [1] is a good overview. [1] http://www.techlawforum.net/post.cfm/gpl-3-overview http://www.techlawforum.net/post.cfm/gpl-3-overview
- cs02rm0 12y ago
  That seems to be GPLv3 rather than LGPLv3 (although it gets a mention).
  - pkorzeniewski 12y ago
    Oops, you're right.. Damn, all these licences are so confusing :)
    - testbmaa 12y ago
      All the more reason not to use them so widely. They sometimes are invasive and behave like a virus (GPLv3). PyQt4 vs pyside is a good example of licensing done wrong, I am not sure licensing a library under GPL would help others as it restricts the projects using them to use only GPL. It means that if you just link to it (just use the names in your program and rely on the client to have installed the right library) then your project needs to be at least the same version of GPL. Then we have pyside who reinvents the wheel for people who cannot afford to pay for a simple layer between python and qt4. LGPL is fine though for such uses. But the main point I want to make is that people using those license seldom read them entirely, which makes it actually a big show stopper and ruin their effort to help the community.
      - belorn 12y ago
        There is this loud minority that only find value in software if they can slap some restrictions on it, and then get upset that GPL won't allow it. That people can be so self-absorbed that they can't enjoy being given software for free is sad. It is also harming the community, and ruining the work of so many people.
giovannibajo1 12y ago
The main difference for the potential embedded user base is that LGPLv3 makes explicit (rather than implicit) that users must be able to run custom code (= modified qt) on the embedded devices; if your device is locked down (e.g.: no possibility to do firmware upgrades, or digital signature checks), you must buy a commercial license. This is true for applications that use the new LGPLv3-only modules. For applications using LGPLv2.1 modules, you can still try to freeload by sticking to a literal reading of the license, though I would personally advise against it.
- deleted 12y ago
  [deleted]
  - giovannibajo1 12y ago
    Right, I stand corrected.
    - belorn 12y ago
      (Sorry, I miss clicked and deleted the wrong comment. Here is it but in wrong order.) Actually, if the device has no possibility to do firmware upgrades, then that is in compliance with the the license. GPL has an exception which say that the requirement "does not apply if neither you nor any third party retains the ability to install modified object code on the User Product (for example, the work has been installed in ROM)". The goal is that "modified object code is in no case prevented or interfered with solely because modification has been made". It is targeting the intentional anti-consumer and anti-property design in which the manufactorer retain control of the device, after sale. If you don't intentionally prevent others from modifying the device, then the product is unlikely to be effected by the license requirement. (The quoted parts are directly taken from the GPL license text, section 6).
deleted 12y ago
[deleted]
coldtea 12y ago
Hmmm, a lot of companies wont touch it now even with a 100-foot pool.
- drdaeman 12y ago
  Why? They have just added an licensing option to a set of existing ones. LGPLv2.1 and proprietary commercial licensing are still here for anyone who wish to restrict their users.
  - jordigh 12y ago
    No, no, I thought that too, but it's not like that. They are adding some new modules that are LGPLv3 only. The old ones are LGPLv2.1, with an option to use LGPLv3, I assume. Hard to tell from their description without reading the legalese, but they'll need something like it, because v2.1 and v3 are incompatible with each other.
- jordigh 12y ago
  Why not? If they have problems with code sharing, they can still touch it like they could always do: buy an exception. I'm surprised that LGPL exceptions are a good way to make money, but this v2.1 -> v3 change doesn't change a lot of Digia's exception-selling business. Selling GPL exceptions make more sense to me, whereas LGPL exceptions are still a bit more mysterious, but I guess they both work.
- shmerl 12y ago
  Not all companies are sick with DRM.
  - coldtea 12y ago
    No, just any company or programmer wanting to use QT to make a iPhone or Android app to sell (and not give the source away). Maybe he can still pay for a different licence deal, but the free option is now gone.
    - 12y ago

74 points by Tsiolkovsky 12y ago

If you have no idea (like me) what's the difference between LGPLv2 and LGPLv3 and what are the implications, here [1] is a good overview. [1] http://www.techlawforum.net/post.cfm/gpl-3-overview http://www.techlawforum.net/post.cfm/gpl-3-overview

cs02rm0 12y ago
That seems to be GPLv3 rather than LGPLv3 (although it gets a mention).
- pkorzeniewski 12y ago
  Oops, you're right.. Damn, all these licences are so confusing :)
  - testbmaa 12y ago
    All the more reason not to use them so widely. They sometimes are invasive and behave like a virus (GPLv3). PyQt4 vs pyside is a good example of licensing done wrong, I am not sure licensing a library under GPL would help others as it restricts the projects using them to use only GPL. It means that if you just link to it (just use the names in your program and rely on the client to have installed the right library) then your project needs to be at least the same version of GPL. Then we have pyside who reinvents the wheel for people who cannot afford to pay for a simple layer between python and qt4. LGPL is fine though for such uses. But the main point I want to make is that people using those license seldom read them entirely, which makes it actually a big show stopper and ruin their effort to help the community.
    - belorn 12y ago
      There is this loud minority that only find value in software if they can slap some restrictions on it, and then get upset that GPL won't allow it. That people can be so self-absorbed that they can't enjoy being given software for free is sad. It is also harming the community, and ruining the work of so many people.

giovannibajo1 12y ago

The main difference for the potential embedded user base is that LGPLv3 makes explicit (rather than implicit) that users must be able to run custom code (= modified qt) on the embedded devices; if your device is locked down (e.g.: no possibility to do firmware upgrades, or digital signature checks), you must buy a commercial license. This is true for applications that use the new LGPLv3-only modules. For applications using LGPLv2.1 modules, you can still try to freeload by sticking to a literal reading of the license, though I would personally advise against it.

deleted 12y ago
[deleted]
- giovannibajo1 12y ago
  Right, I stand corrected.
  - belorn 12y ago
    (Sorry, I miss clicked and deleted the wrong comment. Here is it but in wrong order.) Actually, if the device has no possibility to do firmware upgrades, then that is in compliance with the the license. GPL has an exception which say that the requirement "does not apply if neither you nor any third party retains the ability to install modified object code on the User Product (for example, the work has been installed in ROM)". The goal is that "modified object code is in no case prevented or interfered with solely because modification has been made". It is targeting the intentional anti-consumer and anti-property design in which the manufactorer retain control of the device, after sale. If you don't intentionally prevent others from modifying the device, then the product is unlikely to be effected by the license requirement. (The quoted parts are directly taken from the GPL license text, section 6).

deleted 12y ago

[deleted]

coldtea 12y ago

Hmmm, a lot of companies wont touch it now even with a 100-foot pool.

drdaeman 12y ago
Why? They have just added an licensing option to a set of existing ones. LGPLv2.1 and proprietary commercial licensing are still here for anyone who wish to restrict their users.
- jordigh 12y ago
  No, no, I thought that too, but it's not like that. They are adding some new modules that are LGPLv3 only. The old ones are LGPLv2.1, with an option to use LGPLv3, I assume. Hard to tell from their description without reading the legalese, but they'll need something like it, because v2.1 and v3 are incompatible with each other.
jordigh 12y ago
Why not? If they have problems with code sharing, they can still touch it like they could always do: buy an exception. I'm surprised that LGPL exceptions are a good way to make money, but this v2.1 -> v3 change doesn't change a lot of Digia's exception-selling business. Selling GPL exceptions make more sense to me, whereas LGPL exceptions are still a bit more mysterious, but I guess they both work.
shmerl 12y ago
Not all companies are sick with DRM.
- coldtea 12y ago
  No, just any company or programmer wanting to use QT to make a iPhone or Android app to sell (and not give the source away). Maybe he can still pay for a different licence deal, but the free option is now gone.
  - 12y ago