Qt 4.5 will be released under the LGPL | Hacker News Reader

Qt 4.5 will be released under the LGPL

arstechnica.com

86 pointsicefox18 comments

This is awesome. The major disadvantage of using Qt was the huge price for a license if you didn't make opensource software. Now that they took that away I guess I will never look back to GTK or wxWidgets. Thank you a million times Nokia.

As a bootstrapped hacker who just let his qt license expire this is awesome news. Score on for the guy who didn't pay his bills.

Agreed. The Qt commercial licensing was unusual in that you had to buy it before you started coding -- any code written against the free version could never be commercially distributed, even if you later bought a commercial Qt license.

I'd been avoiding Qt precisely for this reason; I didn't want to pay for a license for experimentation, but I also didn't want to restrict my options in the unlikely case that the experimentation turned into something worthwhile.

I notice they are adding LGPL to the list of licensing options... Why would anyone continue to choose the commercial licensing option when an LGPL one is available?

The commercial licensing still has value, because LGPL has the same restrictions as GPL, minus the clause that states that you can't combine GPL with licenses that have more restrictions that it.

For example, it must be possible for customers to link your application to newer versions of the LGPL licensed library. And any modifications you make to the library itself must be also licensed under LGPL or compatible.

In that case, they really need to change their commercial licensing model. It may be hard for a hobbyist to tell if they'll need a commercial license ahead of time, but it will be even harder for a commercial company to tell if they'll eventually need an LGPL exception.

Trolltech provides a trial license for the very purpose you are describing. When evaluating Qt for a commercial project you can get a trial license and see if Qt would work for you.

If you want to link statically against an LGPL'ed library you have to distribute your object files. I've switched one library I maintain to dual LGPL / MPL for that reason. A lot of companies have bans on the LGPL because it's still an annoyance for them.

This is exciting for us too. Our engine uses some small parts of Qt, but we'd intentionally kept the usage somewhat limited in case we ever wanted to factor it out so that we could deliver our stuff in some form other than as a web service. It's nice having that out of the way.

I'd also had a chance to chat with some of the Trolls before the news broke since my initial reaction was, "What does this say about Nokia's future commitment to Qt?" I'd guessed that Nokia would do free-as-in-beer licensing, but not free-as-in-our-competitors-can-fork-it licensing. Turns out that there are some reasonably sane business reasons for the switch.

It'll be interesting to see how Nokia plays their cards in the just heating up mobile platform wars and how Qt factors into that.

Official press release: http://www.qtsoftware.com/about/news/lgpl-license-option-add...

Some of my own thoughts on it: http://benjamin-meyer.blogspot.com/2009/01/qt-45-will-be-rel...

dot.kde.org article: http://dot.kde.org/1231920504/

With the recent (well, last few years) advancements on GTK for WIndows I've been looking at PyGTK as a cross-platform, native looking GUI option.

Time to check out PyQT.

I've found PyGTK is a joy to use, but the major downside for me is that it doesn't use native controls.

It mimics them with a theme on Windows, so presumably it looks okay (though I suspect it misses the finer details).

But on OSX, with its very distinctive widgets, GTK just looks horrible :(

Qt's a bit better than GTK on OS X, but it's still, sadly, not great. Qt tend to look out of place on OS X. Some of it seems curable -- e.g. simple things like getting margins right and so on, and other things are more complicated since in places Qt is trying to support interface elements that aren't used on OS X.

You can kind of see this with a few high-profile Qt apps like Google Earth, Opera, and the Last.fm client, the last being the best looking, but mostly because Max has put a lot of effort into making it not look like ass.

> Time to check out PyQT.

Not so fast. The Python bindings are still licensed under GPL (and a commercial license) by Riverbank.

Creating Python bindings to Qt is a lot of work, to be sure, but it's not rocket science. Either Riverbank will LGPL PyQt, or someone else will no doubt come along and write their own LGPL bindings.

Either way, this is big news. In general, there has been a lot of hang-wringing about "which GUI toolkit to use", and the main (and pretty much only) reason for not using Qt (its licensing) has just evaporated into thin air.

From the PyQT website: "Like Qt itself, PyQt is provided under a number of licenses depending on how it is going to be used. In fact, we try and follow Trolltech's licensing model as closely as we can." - http://www.riverbankcomputing.co.uk/commercial/pyqt

So I'd guess from this that later versions of PyQt will be released under LGPL, though of course that's not yet certain.

BTW here is my take on it as a current Qt commercial licence owner: http://successfulsoftware.net/2009/01/14/qt-to-be-available-...

Nice.. this will be a big win for writing commercial linux apps.

One of the best GUI toolkit ever. Now available for free almost without any restrictions.

I hope it will encourage developers to create multi-platform applications. Don't forget that desktop programs are in many cases much more useful then their web based competitors.

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