QT is a highly-polished, well documented modern GUI toolkit – some consider it to be the best GUI toolkit for UNIX compatible systems.
It’s well-known for being used in the KDE desktop environment, the biggest competitor to the GNOME / GTK desktop. There was some controversy in the past surrounding KDE’s use of QT, as it was not originally available under any open source license. QT 2.2 added the GPL to available licenses, and while this was good for free software projects, the requirements of GPL compliance still limited it’s widespread adoption.
Nokia will finally release the next major version of QT (4.5) under the LGPL as well as existing GPL/commercial licenses. Once QT is LGPL it will put them on the same licensing footing as Gnome’s GTK.
General response seems to be along the lines of “this is huge!“, “no more $5000 licenses!“, “excited!“, “huge win for cross-platform development”, “sounds like Nokia is keen on pushing QT as defacto standard GUI toolkit“, “the change is needed to lower the cost barrier compared to other mobile platforms“.
But what’s the real impact of this change? Will we see developers dropping GTK in favour of QT? Will people flock in droves to the Symbian platform with QT on top? Is KDE going to become the de facto desktop?
No. My guess is “not much change, business as usual”. Alex has some interesting thoughts on it as well, as I knew he would when I asked him
I think in the short term, we will see a significant amount of noise about this. It’s particularly relevant in the mobile space since Nokia announced the port of QT to Symbian S60 in October. In some ways, this move was innevitable given Nokia’s acquisition of Trolltech (the company behind QT, now called Qt Software), and the establishment of the Symbian Foundation.
I think Nokia are hoping they will see a few more developers adopt Symbian as a result of this move, and it makes a nice soundbite and story – but my suspicion is that a toolkit on it’s own is not sufficient (the rest of the platform needs to be familiar and friendly too).
Given the momentum, ecosystem and companies around Gnome (Ubuntu, RedHat, Google, Sun, …) I don’t see Gnome / GTK being visibly impacted any time soon. There’s an outside chance the next major version of GTK will be ditched in favour of QT, but I suspect inertia and fear of capitulation to Nokia will prevent this happening.
Finally – Alex wonders why we’re tied so thoroughly to widget toolkits. I suspect this will change. WebKit and WebOS initiatives may make GTK and QT much less significant than it used to be, as we see native apps marginalised in favour of HTML++ for most application developers. Not least because it’s only going to get harder to find “low level” developers (with Java being taught instead of C/C++ in schools and universities), and internet apps have the “cool” factor without (allegedly) needing so much of the blood, sweat and tears.
There will still be a need for someone to write the toolkits like GTK and QT – after all, how will web browsers display themselves? – but the apps on top just won’t care. The big deal here is what ships in mobile application stores in the future. With the Apple iPhone app store seeing 15,000 apps and 500m downloads (and Apple redefined drag ‘n’ drop interface building), and Palm Pre App Catalog effectively offering a web widget store, our perception of what’s in an application and what’s needed to run one is going to go through some subtle but dramatic changes over the next year or so.