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Announcing the Qt Automotive Suite

blog.qt.io

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Re: Announcing the Qt Automotive Suite

#41

Post by distances »

Grishnakh wrote: post #31
joezydeco wrote: post #10

Earlier quoted context omitted.

The LGPL thing is not really the issue here. It's how Trolltech/Nokia/Digia/QtCo approached the payment of a commercial license. It's always been explained to me by the sales people that "you cannot switch licensing models mid-stream". So if you're planning to go commercial, you start commercial. It's not really about closing the deal as much as making sure the Trolltech developers were paid during the time you neede…

But do you even need a commercial license to sell your product commercially? It's LGPL, so surely you can just keep the Qt library LGPL. If you're not changing anything at all in Qt (and you really shouldn't be...), and you don't care about getting support (the docs are good enough for you), then why do you need a commercial license at all?

There are still some cases where you need a license, like Qt for Device Creation (https://www.qt.io/qt-for-device-creation). Or perhaps you need static linking, or want to include some Qt code in the app proper for one reason or another.

Re: Announcing the Qt Automotive Suite

#42

Post by ronjouch »

FigBug wrote: post #35
ronjouch wrote: post #28

Earlier quoted context omitted.

Thanks for digging this up for me :) . However, 0) leaves room for interpretation: when it says "to recombine or relink the Application with a modified version of the Linked Version to produce a modified Combined Work" , should we read this as "the very same Version, modified to accommodate some needs while keeping API compatibility in mind" or a much-broader "any later Version, maybe even upstream, that may have rec…

You absolutely can't use GPL libraries like this. If you use a GPL library you are required to release your entire application source code under a GPL compatible license. With LGPL libraries I find a lot of developers aren't aware of the relinking requirement, but it does get enforced. That's why you won't find LGPL libraries being used in the iOS App Store and why you need to buy a commercial license for Qt for mobi…

"If you use a GPL library you are required to release your entire application source code under a GPL compatible license."

Thanks for contradicting. I almost swore nonsense, but I'm so unsure about everything when it comes to licensing that I thought I'd read about it first, and you're right. I'm flabbergasted; never understood this, and never met anyone confident enough about their understanding of GPL to contradict my (wrong) understanding.

But then, does this mean anyone can ask for the source of closed-source software that use GPL code, like the ones below? (I just dug two random examples).

- AutoDesk software. Uses GPL components at http://www.autodesk.com/company/legal-notices-trademarks/ope... -- EDIT: alright these are all _L_GPL libs, which means just distributing the (potentially modified) lib sources is okay as long as you don't link statically. Right?

- HipChat Enterprise. Server-side, but distributed, to be run by enterprises on their own servers. Uses GPL components at http://sources.hipchat.com/ -- EDIT: in this case, all the GPL components seem to be basic GNU utilities, used by calling binaries rather than being coupled to the commercial software by a linking / shared object mechanism. Right?

Re: Announcing the Qt Automotive Suite

#43

Post by distances »

pjmlp wrote: post #39
giovannibajo1 wrote: post #37

Earlier quoted context omitted.

I don't think it has to do with language but rather with interface patterns. Qt Widget was made to do native desktop apps like Word; QML was made to do touch apps like on mobile. Embedded has shifted to adopt touch screen and copy interface patterns from mobile (where touch based interface were innovated first). You don't want a Word-like app in your car dashboard, but a iOS-like app.

Except that on iOS you can do everything in Objective-C/Swift if you feel like it. Same applies to Android, UWP and even Tizen with their respective native languages. So it is a conscious decision not to provide C++ APIs besides the old QtWidget and make developers use QML and its compiler instead, as far as I understand it.

It's not as clear-cut as that. This is a case for automotive, and there isn't a single native UI widget set that Qt could use/mimic. It absolutely makes sense to use QML for custom UI development, it really shines there -- using Qt widgets for custom UI on touch screens would be madness.

I've used Qt myself for desktop, mobile, and embedded development. For mobile and embedded I would not use widgets, and probably not even for desktop. I understand why the widgets still has staunch fanbase, but they do not belong everywhere.

Re: Announcing the Qt Automotive Suite

#44

Post by CamperBob2 »

sigzero wrote: post #36
karmicthreat wrote: post #3

So I'm remaking a product and was approaching qt about the commercial version. The rep was very insistent that I can not develop an internal prototype using the open source license and then move to the commercial license. So that makes qt pretty unattractive to me since I have to pony up cash and hope it's good. What I would like is something like electron that can run on a frame buffer. What's the current state of t…

What's his reasoning? As long as you purchase the commercial license prior to releasing why should they care?

Agreed, that policy is utterly nuts.

The incentives for me to comply with those terms are nonexistent, which is never a sign of a good contract.

Re: Announcing the Qt Automotive Suite

#45

Post by mjevans »

distances wrote: post #12
lultimouomo wrote: post #9

Earlier quoted context omitted.

That sounds like FUD* - Qt's LGPL is LGPL without modifications, so it does not have any quirk. Is it written in the commercial license that you cannot buy it if you have used the LGPL license? * Not accusing you of course; I'm totally convinced that it can come from a misguided sales rep trying to close a deal as early as possible.

Qt-as-the-company has always made it very clear that you can't switch your Qt LGPL/GPL project to a commercial one if you didn't start with the commercial Qt license from the beginning. You're right, it does sound a bit nasty. No, I haven't read the license myself. It's been brought up multiple times on official Qt blog comments and mailing lists, though. Edit: checked it now, and it's clearly written at https://www.…

It would be nice if they had some form of migration publicly stated. For example something like this:

If your project decides to go commercial the initial license term will include a cost of conversion based on the quantity of code already written.

It would be interesting if they expressed that rate as something like:

A gz -1 compressed tarball of the affected source code will be created, the size (in bytes) multiplied by X is the maximum fee we would charge for retroactive licensing.

I choose the wording 'maximum' there as it still allows them to offer better deals under other circumstances.

Re: Announcing the Qt Automotive Suite

#46

Post by FigBug »

ronjouch wrote: post #42
FigBug wrote: post #35

Earlier quoted context omitted.

You absolutely can't use GPL libraries like this. If you use a GPL library you are required to release your entire application source code under a GPL compatible license. With LGPL libraries I find a lot of developers aren't aware of the relinking requirement, but it does get enforced. That's why you won't find LGPL libraries being used in the iOS App Store and why you need to buy a commercial license for Qt for mobi…

"If you use a GPL library you are required to release your entire application source code under a GPL compatible license." Thanks for contradicting. I almost swore nonsense, but I'm so unsure about everything when it comes to licensing that I thought I'd read about it first, and you're right. I'm flabbergasted; never understood this, and never met anyone confident enough about their understanding of GPL to contradict…

I didn't look at all the LGPL/GPL code they are using, but your understanding seems correct.

Re: Announcing the Qt Automotive Suite

#47

Post by Grishnakh »

distances wrote: post #41
Grishnakh wrote: post #31

Earlier quoted context omitted.

But do you even need a commercial license to sell your product commercially? It's LGPL, so surely you can just keep the Qt library LGPL. If you're not changing anything at all in Qt (and you really shouldn't be...), and you don't care about getting support (the docs are good enough for you), then why do you need a commercial license at all?

There are still some cases where you need a license, like Qt for Device Creation ( https://www.qt.io/qt-for-device-creation ). Or perhaps you need static linking, or want to include some Qt code in the app proper for one reason or another.

Ok, but if you stick with dynamic linking and don't insert Qt code into your app, then you don't need a commercial license, right? Why would you insert Qt code in your app anyway? That kinda defeats the point of using a library. As for static linking, why would you opt for this over dynamic linking anyway? Dynamic linking is better since other applications can share the libraries. Static linking on a PC platform is basically a hack for poor library management.

As for Qt for Device Creation, I looked through that and didn't see why you'd need a license there, unless they're selling optional components or plug-ins which are not LGPL licensed (which appears to be the case with things like "Qt Quick 2D Renderer" and "Qt Virtual Keyboard").

I even tried out the questionnaire at www.qt.io/download: if you select "Commercial deployment" for development and then say that you're doing dynamic linking, don't have any concerns about reverse-engineering, and can comply with the LGPL, it recommends you use the open-source LGPL'ed version.

Re: Announcing the Qt Automotive Suite

#48

Post by lmm »

ronjouch wrote: post #42
FigBug wrote: post #35

Earlier quoted context omitted.

You absolutely can't use GPL libraries like this. If you use a GPL library you are required to release your entire application source code under a GPL compatible license. With LGPL libraries I find a lot of developers aren't aware of the relinking requirement, but it does get enforced. That's why you won't find LGPL libraries being used in the iOS App Store and why you need to buy a commercial license for Qt for mobi…

"If you use a GPL library you are required to release your entire application source code under a GPL compatible license." Thanks for contradicting. I almost swore nonsense, but I'm so unsure about everything when it comes to licensing that I thought I'd read about it first, and you're right. I'm flabbergasted; never understood this, and never met anyone confident enough about their understanding of GPL to contradict…

> But then, does this mean anyone can ask for the source of closed-source software that use GPL code, like the ones below? (I just dug two random examples).

If their software is a derivative work of someone else's code then they can't distribute their software without a license from the copyright holder of that code. In the case of the GPL, that licenses them only to distribute their code under the GPL. If they are distributing their software other than under the GPL, then that is copyright infringement (in the same way as if they had made a derived work of some non-GPL code and distributed that), they lose their license, and any holder of a copyright on the code that their software was a derivative work of could sue them for copyright infringement. (In theory they sue for damages; in practice the copyright holder of GPLed code they made a derivative of will usually settle for compliance and an agreement to have their future releases audited).

What constitutes a derivative work is a question for the courts. It's generally accepted that any program that uses a library is a derivative work of that library, and a program that invokes another program at arms length or via a standard interface is probably not a derivative work of that program. The exact boundary is unclear; there's a case to be made that a program that is tightly coupled to another program and invokes it via piped commands might still be a derivative work even though it's not shared objects.

The LGPL is an entirely different license from the GPL.

Re: Announcing the Qt Automotive Suite

#49

Post by jschwartzi »

lultimouomo wrote: post #15
karmicthreat wrote: post #13

Earlier quoted context omitted.

I found the applicable text: https://www.qt.io/terms-conditions/ *NOTE: If Licensee, or another third party, has, at any time, developed or distributed all (or any portions of) the Application(s) using an open source version of Qt licensed under the terms of the GNU Lesser General Public License, version 2.1 or later (“LGPL”) or the GNU General Public License version 2.0 or later (“GPL”), Licensee may contact The Qt…

That is very interesting. Note that they are not precluding you to switch, but they do reserve the right to sell or not sell to you the commercial license after you've used the LGPL. It sounds like an empty threat to me (if you talk to the sales rep and say "I have an internal prototype and I would like to buy the commercial license to finish and distribute it", will they say no?), but one should definitely consider…

It's not an empty threat so much as it's an opportunity for them to gouge you later when your product is already highly dependent on their product.

Re: Announcing the Qt Automotive Suite

#50

Post by kevin_thibedeau »

distances wrote: post #41
Grishnakh wrote: post #31

Earlier quoted context omitted.

But do you even need a commercial license to sell your product commercially? It's LGPL, so surely you can just keep the Qt library LGPL. If you're not changing anything at all in Qt (and you really shouldn't be...), and you don't care about getting support (the docs are good enough for you), then why do you need a commercial license at all?

There are still some cases where you need a license, like Qt for Device Creation ( https://www.qt.io/qt-for-device-creation ). Or perhaps you need static linking, or want to include some Qt code in the app proper for one reason or another.

You can statically link LGPL. Your only obligation is to provide object files so that customers can relink.
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