Trolltech to Extend Dual Licensing to Qt for Windows

Trolltech, maker of the Qt toolkit which forms the basis for KDE,

announced today
that the Qt version for Microsoft Windows will be available under the GPL in addition to its current commercial license offerings for that platform. This change will take place with the release of Qt 4. The Qt version for Linux has been available under a similar dual licensing scheme for several years already. The availability of a GPL'ed Qt for Microsoft Windows will make it much easier to distribute KDE applications that run on the Microsoft Windows platform.

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by jmfayard (not verified)

> Making the applications available on both Linux and Windows
> will eventually put more people on Linux.
> Why?
> Because one of the biggest complaints now is... the program
> I use, or something very similar in look and feel, is not available in Linux.

Since years now, a hell lot of FOSS is available on macosX fixing for free (money and efforts) every gap and lacks the platform had. (For example, everybody uses VideoLan Client and/or mplayer. Having only QuickTime would have been a pain in the ass). If your theory is good, you would have seen a lot of people working as secretary in your office switching to Linux.

Have you ?

Note that I don't care/even welcome the macos port, because Apple will ever remain a niche market, and because there is 40 times less concurrency there than for Win32. The later means that a lot of FOSS app will have a realistic chance there, so it's still a win for "us" if you switch from windows to macosX. (If you switch from Linux to macosX, it's a net loss though).

Win32 is a whole other story.

by Tim Beaulen (not verified)

Since years now, a hell lot of FOSS is available on macosX fixing for free money and efforts) every gap and lacks the platform had. (For example, everybody uses VideoLan Client and/or mplayer. Having only QuickTime would have been a pain in the ass). If your theory is good, you would have seen a lot of people working as secretary in your office switching to Linux.

Have you ?

In the office I work?
No, unfortunatly no.

In other offices.
Yes, I've seen a lot of offices switch from Windows to something else, including linux.

I did never mention FOSS software.
I was talking about software in general.
As in... for example, Dreamweaver or Photoshop for linux too.

It would make lots of people think more about linux, and probably even switch.

If it really would be that way.
I have absolutely no idea... I don't have a magic cristal ball :)
It's just my opinion.

by brockers (not verified)

But the point jmfayard made is spot on. The next movement in terms of MacOSX and Linux is TOWARD OSX. The general rule of thumb is that more people are moving TO OSX from Linux than the other way around. Why? Because, "I can have all the power of a unix system with a nice Mac polish and Microsoft Office natively supported." OSX running Linux apps have HURT Linux, PERIOD!

This is bad news for F/OSS!


by Jose (not verified)

Linux as a OS has no advantages over MacOS but the freedom and the price.
MacOS X is UNIX, it's safe, it does not have viruses, it does not have spyware, so, why to choose Linux when you alredy paid for MacOS X when you bought your computer?.
Windows is a completely different story. I know a lot of people (Joe users) that are worried about virueses and spyware and run antivirus and firewall software consuming their resources and making the system a lot more unstable. I even have one of them running Ubuntu in his laptop (I know it's GNOME, but gnome-volume-manager is a big advantage to GNOME until the media:/ kioslave is released with kde 3.4). If they run kde in their windows machine and use only free software (konqueror/firefox, kmail/thunderbird, openoffice/koffice) then I could say, look at this! In that OS you can have all of this and there's no spyware nor viruses!
I think porting kde to windows could make the switch to linux easier.

by Bob Austin (not verified)

I agree. If linux is to move into a dominant position, businesses and governments must be able to have the applications they current use run in a linux environment. Consider the area of emergency services (Police, Fire and EMS). There are no commercial quality Linux apps available for dispatching, call taking, incident reporting, etc.

Why would a government make a switch to Linux, when it would then have to support two operating systems? One for office apps, another for service operations, it is a nightmare situation. Then there is the problem of using the data generated on one system and importing it to the other system.

The more applications that are cross platform, the better.

Then why would they switch from Linux to Windows? Several reasons. My agency was force to switch to XP from NT4 due to lack of support from MS. NT4 did the job, but it was no longer supported. An agency with 38 stations, a training academy, etc, that is a lot of money. Now if I could do a gradual change to Linux, cause all of the apps were cross platform, the situation changes. I don't have an enormous outlay of cash because MS decides it is time to stop support. I can budget expenses based on my timetable, not MS. And lets not forget the ever popular MS software audits, that cost the agency time and money.

I agree, the cross platform support is critical to making Linux dominant.

Just my two-cents worth

by Bad_Bob (not verified)

Making them suffer != making them switch.

Sometimes I have to use Windows in developing. I use Linux as much as I can, but our company sells Windows software. If I could have all of my favorite KDE apps in Windows, I'd be much happier. Making me suffer, in this case, makes no sense.

by ac (not verified)

Why does your company sell Windows software?

My guess:

a. Your customers use Windows
b. Your customers don't have enough problems with the Windows platform to favor a switch to Linux.

Will the availability of KDE applications on Windows improve the situation?

IMHO no. It will actually make it worse because it solves some problems that Windows user have (see Firefox) and it ports the great features like kioslaves to the windows platform.

by brockers (not verified)

Sometimes you use Windows in developing... You try to use Linux as much as your can but your company sells Windows software. If you could have your favorite KDE apps in Windows, you would be happier. Being able to use those KDE apps in Windows is gonna make you more likely to use Linux... NO? Of course not!

If you need a KDE app and it only runs on Linux... you start up Linux. If you now have it on Windows and you are using it on Windows then why bother starting up Linux. KDE on Win32 HURTS Linux... period! Its a simple fact. Some people (like yourself) will continue to use Linux/KDE, but for the vast majority of people all this means is that their Windows machines will have more/better software for them.


by Bad_Bob (not verified)

So you're saying that choice is a bad thing? That we shouldn't give Windows users F/OSS at all?

What do you think about Firefox, OpenOffice, etc.? Did they hurt Linux?

by ac (not verified)

> What do you think about Firefox, OpenOffice, etc.? Did they hurt Linux?

Actually yes, because Windows user now have a viable alternative to the "bug contaminated", old IE. One less reason to switch to Windows.

by brockers (not verified)

Being on multiple platforms helped Firefox and Open-Office... but they did little to help Linux. Open-office is one of the only possible exceptions that I can think of, because it opened a file format to use on any platform. But the reverse would not be true because KDE's file formats are already open.

Firefox is an extension of Mozilla which is an extention of the old Netscape. Netscape was arguable ported to Linux and not the other way around. And yes, porting Netscape to Linux HURT Windows. Now that Linux/KDE apps will be ported to Windows they will most assuredly hurt Linux.


by Colin (not verified)

Swings and roundabouts. There are many ways to look at this.

As you have said, Joe user generally doesn't care about the OS they use, but they do care about applications and more precisely, getting the task in hand done. In the home environment, this probably isn't going to change much. But in a company, a sys admin who is aware of potential, valid, professional benefits of switching to Linux may rejoice at this news.

If Joe user at work can be gradually migrated to using F/OSS QT/KDE apps on Windows which are also available on Linux and still get the job done, then the OS can be eventually switched over to Linux too with minimal disruption and retraining cost.

by Kåre (not verified)

My parrents use their computer for reading e-mail, paying bills via the web and write documents (Word for now). I installed Firefox and Thunderbird to minimize the risk of viruses and everything was OK. Then later I thought why not even install linux and KDE. Now my favorite browser is Konqueror and my favorite mail reader is KMail, so naturally that was what i planed to install, but they where already used to Firefox and Thunderbird and wanted the same applications under Linux.
If KMail and Konqueror would have been available under Windows they would have been accustomed to them in stead of Firefox and Thunderbird. This is a WIN for KDE and Linux. Exposure to FOSS makes people AWARE of the alternatives and start to understand that the Computer doesn't have to equal Windows.


by aleXXX (not verified)


Why do e.g. mozilla, eclipse and OOo big momentum ?
Because they run on both windows and linux. That's just not the case qith Qt/KDE apps (since there's no free Qt version available).
Having Qt GPL on windows might gain us (KDE) a lot of mindshare and developers.

Qt GPL on windows is just great ! I never thought this would happen. Trolls, you rule !

Now how about QtCore LGPL on Linux/Mac/UNIX ?
IMO this would be easier step than the release of Qt under the GPL on windows.


by ac (not verified)

> Why do e.g. mozilla, eclipse and OOo big momentum ?

Noone questions that Firefox and the rest are successful on the Windows and Linux platform at the moment.

What I question is that this success will move people away from Windows.

by Davide Ferrari (not verified)

Don't know you, but I'm not "fighting" for a world without Windows, I'm "fighting" for a world where one could choose in TOTAL freedom the programs and operating system to use, without being frustrated by closed standards or things like this. And as the world is going, the standards are dictated by the applications, and be the applications spreading. For example, the succes of Firefox will be probably make the web a more standard world. And that's good.

by brockers (not verified)

Like it or not, the success of software GPL'ed software on the desktop was a total failure until their was a GPL'ed OS. If Linux dies on the desktop because of KDE's success, we will loose our freedom. When KDE ends up on Windows and developers discover the power of KDE do you honestly think they will care if their new KDE apps are able to run, work, or even compile on Linux? This same thing already happens on firefox, where there are tons of plug-ins that work on Windows but no other OSes. Programs that use Windows closed API's, closed standards because they are the de-facto standard. So what happens when KDE on Windows is actually better than KDE on Linux?

Those who are not willing to fight for their freedom will eventually loose it. And an FOSS desktop OS is a huge part of that equation. Porting KDE to Windows only contributes to the destruction of our freedom.


by Daniel Franke (not verified)

In my eyes the best argument in this thread. All those windoze-devs who never bothered to have a look at linux/kde theirself. Eventually they will adopt kde-apps they like, enhance them even - but as windozw-kde-apps, using not only the KDE/Qt-API but native windoze-calls as well (why shouldn't they, they know 'em best, they used it for years). Worst of all, we all are lazy, so, why bother porting back to linux, it works for me (them) *sigh*

in short: kde/win32 is evil (on the long run)


by Davide Ferrari (not verified)

Well, first of all KDE is not a simple application, KDE is a fundamental part of a modern operating system as it could be a GUI. I think that whole KDE will never be ported to win. Look, GTK has been GPL'ed and even LGPL'd from the very beginnings, do we have a Gnome over Windows? No, we have the possibility to run a bunch of GTK+ apps on win32, and that's good cause the users are normally addicted to applications, not operating systems or desktop environments. Moreover, as KDE devolopers stated, Windows is not a 100% POSIX system and KDE needs a POSIX system to work.
And about incompatible changes, you may get surprised but *there* are open source application natively thought and built on win32 and not even ported to Linux or other what? The problem here is simple: if a developer wants to create a portable and opensource application, he will do. If he doesn't, he won't.

by ste (not verified)

> What I question is that this success will move people away from Windows

I know at least 10 people, including me, that switched to Linux after using OpenOffice and Mozilla for a while.

"Get the facts..." ;-)

by brockers (not verified)

And I know a dozen people who have choosen NOT to use Linux because they can run OpenOffice and Mozilla without leaving their precious Halo 2.

I know the facts, and this announcement scares me.


by pinky (not verified)

>Now how about QtCore LGPL on Linux/Mac/UNIX ?

i think that would be a bad idea, two reasons:
1. Trottech would lose the whole GNU/BSD/Mac/Unix market
2. it wouldn't be an advantage for us, it would be only an advantage for people who want to deny us our freedom. But if they deny people freedom, they can at least pay some money to save the development of our and their basis.

by aleXXX (not verified)

Just QtCore, not QtGUI.
QtCore provides: threading, unicode, file access, event loop, containers

You can get the same, also portable:
threading: pthreads ( or a custom wrapper
containers: STL
file access: fopen() and friends, file streams from STL
unicode: isn't there a wide character class in STL ?
event loop: not too hard to write a custom one
So I think not too many customers buy Qt just to use these features. If they just need these features they can find low-cost solutions.

But there simply isn't any alternative to QtGUI, so I think the paying customers pay for the portable GUI and this wouldn't change.


by ricky (not verified)

ohnoes! Trolltech won't be able to make money under the LGPL. You care about a commerial company that much?

by pinky (not verified)

>You care about a commerial company that much?

I care about commercial companies if they develop Free Software, if they develop proprietary sftware i don't care about them that much.

But what would happen if Trolltech would lose their business? Than the KDE Team would have to care about KDE and the Toolkit.
And i don't know if we would find enough people in the community wo would be able and interested to develop Qt on all platforms.

by Philip Scott (not verified)

The original author didn't want this to turn into a big political debate, but it has, so I'll chip in as well.

My point is short and simple; it's that there is no way in FLOSS you can control development, so don't bother. If some guy wants to port KDE to windows, then let him, if not then there's not much to say.

It's not our place to try and force everyone on this planet to switch our favorite OS.

We're just writing cool software. Lets let the developers decide what they want to write and let the users decide what they want to do with the fruits of our labour. Isn't that what Open Source is all about anyway: choice?

by Philip Scott (not verified)

The original author didn't want this to turn into a big political debate, but it has, so I'll chip in as well.

My point is short and simple; it's that there is no way in FLOSS you can control development, so don't bother. If some guy wants to port KDE to windows, then let him, if not then not.

It's not our place to try and switch everyone on this planet to our favourite OS.

We're just writing cool software. Lets let the users decide what they want to do with it.

by Anonymous Specutator (not verified)

> Just say NO to FOSS on Win32.
I have to agree with this. Even if the KDE was ported on Win32, I certain Microsoft will try to stop it through breaking API and/or creating FUD about KDE.

>Make them suffer, because that's the only way they will be willing to switch.
Yep. Let all the windows users suffer then unfold their blindfold and show them GNU/Linux and *BSD. This actually works, I have converted some Windows Users to GNU/Linux with KDE.

by Matt (not verified)

GPLED Qt on Windows->GPLED software on Windows->GPLED software on Linux and Unix and Windows due to Qt's cross platform nature and open source->mindshare and growing acceptance of Qt and OSS-> more skilled developers usinc OSS technology-> some will contribute to KDE and other projects-Trolltech becomes richer as a result of more interest in their product->Qt becomes better.

Therefore, this is a very goood thing and at the very least it won't make Linux a less attractive platform.

by Questioner (not verified)

Does this mean it will be available under the QPL and the GPL just like the Linux version? I would really hope I could still choose the QPL, but heck, I'll take the GPL at the very least!

by Brandybuck (not verified)

This is my concern as well. Trolltech is saying in their FAQ that they are considering the triple license as well. But in the meantime, I really don't think it makes a difference. The FSF has said consistantly that linking to a library with *multiple* implementations is not derivation. This is because you are now coding to an API instead of a specific library. This is what allows non-GPL-but-still-FOSS software to be ported to Qt/Mac. Now that the commercial-only barrier of Qt/Win is gone, it's available to any software with an Open Source license.

by Jaroslaw Stanie... (not verified)

Ah, and let's don't forget what TT says:
- "We want to encourage our users to use and port to Qt 4. We have no plans of releasing Qt 3 on Windows under the GPL license."
- "The C++ compilers from Microsoft, Intel and Borland are not supported by the tools in the GPL version."


KDE is not ported to Qt4 yet. I dont know if end users (not testers/players) may want (or even can) see KDE4-stable this year. Anyway, qt3/win32 project ( is still reasonable and important.

regards / pozdrawiam,
Jaroslaw Staniek / OpenOffice Polska / Kexi Team

by manyoso (not verified)

"Anyway, qt3/win32 project is still reasonable and important."

No, it really isn't.

by MacBerry (not verified)

> No, it really isn't.

Wow. Could you please elaborate?

by ac (not verified)

Why spend work on risking splitting the developer comunity in two parts, one following a then either unsupported or forked platform?

by Kevin Krammer (not verified)

This is about Qt3, not Qt4.

Qt3/Free/Win32 is still needed for any Qt/Free software built on the Qt3 API.

Some software might never get ported to the Qt 4 API

by ac (not verified)

This is exactly what I meant, keeping one part of the developer community in the then stoneage of Qt3 while everyone else moved forward to Qt4. And someone is seriously still putting work into creating such a situation? I don't see what good about that (except that of course everyone is free to do whatever he wants).

by Matt (not verified)

qt3/win32 has been rendered irrelevant with this announcement. qt3/win32 will only hold back Qt 4 GPL (official) and it will only split development communities. It would have been useful had Trolltech not made thin breaking announcement.

But now, I think it is pointless to work on it isntead of KDE or more improtant things. We don't need it anymore! Sorry, it's the truth!

by Jarslaw Staniek (not verified)

Looks like your reasoning is based on your own needs. Do you think that KDE corporate users will switch to newer (stable or unstable) KDE versions everytime as home "hobbyists" often do? You can say "Shut up, I don't care!". And that's good FOR YOU. But lots of users DO care. Companies like SUSE or Lycoris rely on stable releases because, want to provide support for a particular desktop version: the support what is usually longer than, say, 6 months.

A user who purchased eg. SUSE commercial support last year won't be happy to give up and switch to, say, developemnt version on Debian or Slackware because someting so irrelevant for him like newer development libraries are "so cool". These are cool for me (and for you, IF you're developer, I don't know), but for users it's cool if they can get their daily work done. It's cool enough that they have chosen Linux as desktop, ... do you want to force them to switch back to win32 by telling them "Guys you're not at the bleeding edge!"?

So better say "it's my opinion" and not "it's the truth", because it's false for many developers out there. The time for Qt4 and KDE4 will come, but transition needs to be performed smoothly. That's the advantage of GPLed Qt3/win32.

by pinky (not verified)

A great day for Trolltech and the whole Free Software Community.
Not long ago some people told me on this place, that Trolltech would never do that because they would lose to much customers.
It seems like Trolltech has much more customers who develope software for their customers than everyone thought and they don't earn all their money by in-house development.

I think this will give Qt and Trolltech an great boom on windows.
Now everyone can develop Free Software for all platform and also young people can learn programing with Qt and they will bring their favorite toolkit to business when they became grown-up.

Simply great!

by Spy Hunter (not verified)

TrollTech was forced to make this move; I am sure they did not want to. However, if they waited any longer, the QT port being done by the Cygwin guys would have been finished, and there would be GPL QT/Windows anyway; except that it would not be TrollTech's version of QT/Windows.

TrollTech made a smart move here by realizing that this would be bad for QT. The two versions of QT/Windows would have different bugs and incompatibilities, and TrollTech would have no control over the Cygwin QT code. Now everyone can use the same QT/Windows.

Unfortunately, TrollTech may lose a lot of sales to companies doing in-house projects. We can only hope that this move causes a surge of interest in QT, even from companies doing commercial software development. Otherwise TrollTech could be toast.

by Bausi (not verified)

I don't believe that in-house projects will choose the GPL version. This would mean explaining your PHB that you never ever could give away / sell the software without also giving the source.

Dou you think any sane (ha!) PHB would go for that? QT Licenses are cheap in the commercial setting, they're really only a fraction of the total development costs.

by Bryan Feeney (not verified)

There's another reason why in-house teams will want the commerical version: the commerical database drivers that ship with it.

Most businesses choose big expensive databases, even if they go with free development tools, because they're terrified a F/OSS database would corrupt their data over time. For them, Qt Commercial is the only viable version.

by Spy Hunter (not verified)

Not true, a GPL in-house project can be relicensed and then compiled with the QT commercial edition and sold, as long as the company holds the copyright on the code (which they always do). You're never locked into the GPL if you hold the copyright.

by U (not verified)

I want to congratulate TrollTech for this smart move, this will allow not only to have more Qt based applications on windows it will make the Linux market share grow.

This move will bring benefits to all, OpenSource Community, Linux, Trolltech, everyone.

by cies (not verified)

Why would we support KDE on windoze, i think a lot of support is so called 'community support'.

Then you will see this a lot: do you run on windows? Yes? G'bye!

Or am i the only one fearing/hoping/expecting that windows users will be 2nd class users in the community?

by pinky (not verified)

i don't see, that the whoe kde will be ported to windows.
I think it will be 'only' some key applications.
So i don't think many people will come from windows into the kde-community. If they like programing they may come in the Qt newsgroups or forums, but there already windows and macOS people and there is no problem.

by Cloaked Penguin (not verified)

I don't know how well you know the KDE architecture. What needs heavy engineering to be ported is Libs. The applications depend on Libs, not on the underlying system except for things like kernel maintenance apps that are not even useful in Windows.

If done well, the applications that already compile for Linux/BSD/etc. should compile without changes with the Windows kdelibs headers. Maintenance will be done just like it's always done.

by Troy Unrau (not verified)

The scope of KDE on UNIX isn't just in the libs.

For example, in kdebase we have kicker and kwin (as examples) which rely-on/exist-due-to X, as well as kdm, kdesktop, etc.

Programs dock into kicker for system tray, etc. but would have to be reworked to dock into explorer's systray. Or kicker would have to be rewritten.

Kcontrol modules would have to be rewritten or dropped due to redundancy with the windows control panel. Screensavers would likely be entirely dropped. Session management would go away, since it uses feature of X, or reimplemented to be compatible with windows.

File dialogs, file property dialogs, etc. would all need to be rewritten or modified (this is kdelibs, I know)... Even tooltips in konq, which display the unix file permissions would have to be redone.

Support for Konqueror plugins for flash and related would have to rewritten to use the windows equivalents.

Arts would have to play to DirectSound - kmix would be redundant.


What I would look forward to are KHTML based windows browsers (not konq port) which will help the greater cause of website standards and interoperability. If a bunch of people are using KHTML, more website are likely to work in KHTML. (and gecko for that matter).

Also, I look towards the possibility of Qt+OOo becoming a staple (might be a wet dream though).


that bored? read my boring blog at

by Pat (not verified)

that we'll get w32 qtdesigner gpl too? and is there a gpl qt IDE (other than kdevelop soon :)) that will be release with it?