> I don't even understand how is that possible, since Qt Creator is GPL3.
very simply because it isn't possible and the article is just wrong. You can entirely use LGPL Qt Creator to develop proprietary apps. What you mustn't do is e.g. ship a modified version of Qt Creator as part of for instance an embedded SDK and not ship its source.
The part quoted is explicitly about the QT commercial license. Apparently, you can't use QT commercial with non-qt commercial (and Qt Studio non-commercial).
And probably this is done to be able to sell the IDEs, maybe based on n. of users, etc. Never bought Qt so I don't know how they license "users".
very simply because it isn't possible and the article is just wrong. You can entirely use LGPL Qt Creator to develop proprietary apps. What you mustn't do is e.g. ship a modified version of Qt Creator as part of for instance an embedded SDK and not ship its source.