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Comment by Buttons840 | Hacker News Reader

Another concern for lean startups and hobby projects are that you cannot develop them without first paying for a Qt license. Their licensing clearly states that you cannot transition from the open source license to a commercial license.

I've spent some time working on a desktop application I hope to sell, but I wont consider Qt, because I'm not even sure I will follow through and finish the product. When it's just a hobby class side-hustle, my first step isn't giving Qt $200 this month, and $200 next month, while I work on my side project for 2 hours a week after the kids go to sleep.

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This.

There is the "small business plan" which reduces it down to $500/year, which isn't outrageous, but it's still $500 for something I probably won't get that value out of because of the likelihood of the project ever finishing.

Instead, I'll find other ways to do it. If Qt was free under $X, $500 under $Y, and $$$ over $Y it's a much more persuasive argument. Unreal manage it :)

As I understand it, Qt is released under a mix of GPL and LGPL, so as long as you release the source code of your application you should be fine.

I'm not sure how they can prevent you from transitioning from an open source license to a commercial license? You can develop your app for a year either as open source or privately without releasing anything, and then decide to purchase a license? Not sure if I'm missing something, but how does could they prevent this (legally or practically)?

The license explicitly specifies that you cannot start developing using the free license and then purchase a commercial license when going commercial.

Can you please cite and link the relevant part?

> If I have started development of a project using the open source version (LGPL), can I later purchase a commercial version of Qt and move my code under that license? This is not permitted without written consent from The Qt Company. If you have already started the development with an open-source version of Qt, please contact The Qt Company to resolve the issue. If you are unsure of which license or version to use when you start development, we recommend you contact The Qt Company to advise you on the best choice based on your development needs.

https://www.qt.io/faq/tag/qt-commercial-licensing?hsLang=en

You should be fine with the LGPL license of Qt.

I would like my application to be easy to distribute. I was hoping to distribute it as a single executable file. I don't think this is possible with the LGPL?

You would distribute it anyway as one file, because you're going to pack it into something which does the install. i.e. dmg/pkg file, installer, Linux package, etc.

I don't think I've ever seen a Mac app which consisted of only one file. The whole idea behind .app apps is that they consist of several files.

> I was hoping to distribute it as a single executable file

I don't know of any applications whose scope would require to use Qt to come as a single file.

The installer (be it dmg, exe, pkg, whatever) will, but then it's not a problem with the LGPL.

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