Qt commercial licenses?

Question

Does anyone know the details of the Qt commercial license? Cost? Hidden policy gotchas, single and multi platform etc?

Forgive my laziness, however their website offers few details and I thought I would ask here about anyone's specific experiences prior to submitting to the sales pitch.

Is the commercial vs open source installation different in license only?

What's to keep me from developing something in the Open Source version then buy the commercial license other than their policy?

I think they might sell more licenses if they decreased the margin a bit...

I do like the platform and it has been said that it's worth the expense. Thanks in advance for your thoughts.

UPDATE: Qt will become LGPL Link

Answer 1

AFAIK (sorry, I'm lazy to), the only difference is the license. There is nothing keeping you from developing something in the open source version and then buy the commercial license. The important part is that you cannot distribute nonfree code while using the open source license. What you do with it in house is up to you.

Answer 2

With QT Commercial License you have support directly from trolltech's internals, you can use some widgets that trolltech uses internally, and of course you can use QT to develop commercial applications that you don't have to ship the code with the software, but just binaries. Those were some that I was interested in earlier (it was about 8 months ago) but maybe they have changed something I don't know but you can read more here:

http://trolltech.com/products/appdev/licensing

Answer 3

3months ago:

one platform (win/linux/mac) desktop edition 2500€

one platform (win/linux/mac) desktop light edition 1350€

two platforms, desktop 3750€

two platforms, desktop light 2270€

three platforms, desktop 5500€

QSA addon +1500€

Answer 4

@Egil (not in comment because quote did not fit)

No, one must buy a Commercial license before starting developing a commercial software

Quote from link

You must purchase a Qt Commercial License from Qt Software or from one of its authorized resellers before you start developing commercial software. The Commercial license does not allow the incorporation of code developed with the Open Source Edition of Qt into a commercial product.

...or did you mean that there is nothing stopping you, except you own conscience

Answer 5

We paid for the licence of one Qt edition (the Windows version) for one year with support. This gives you:

• a personal licence file which allows you to compile Qt. This may be required as you may want some features/plugins enabled.
• access to their support which is one the best that i have ever used. You ask your question by email and receive a response promptly (generally on the same day). I once asked a question and got a first response with a test program written by the support staff. We further discussed the issue on this basis instead of abstractly. That was quite nice.
• you have access to their publication and news.
• you also receive new releases of the Qt product.

My understanding is that you can use the free version for developing your application, but then your application should be also free. If that is not what you want, you should buy a licence from them.

It is really a nice platform for developing applications. The licence cost should not stop you, if you can afford it.

My experience until now was quite good as you may know by now :-)

Answer 6

@epatel (Not in comment because I don't have enough reputation)

What I meant is that you can develop software in house with the free license as long as you don't sell it. You might plan to sell it in the future, but the software is not commercial before you make it available. You don't need a license from Trolltech that allows you to distribute closed, commercial software until you actually plan to sell the software.

For instance, it is completely legal to develop closed, in-house software with the free license. As long as you don't distribute it, you don't need a commercial license.

Answer 7

According to the QT licensing FAQ:

Can I switch from using Qt under the LGPL to commercial afterwards? link

Users of the LGPL versions of Qt need to comply with the LGPL licensing terms and conditions. Qt’s commercial license agreement contains a restriction that prohibits customers from initially beginning development with the LGPL licensed version of Qt and then transitioning to a commercial version of Qt.

PS: I have noticed the date the last comment was posted on.

Answer 8

so in a nutshell the QT platform has a phone home feature in it some where.