The parent comment implied that it was still the case however, which is misleading; it has been available under GPL rather than the non-commercial "QPL" since 2000, and under the less-restrictive LGPL since 2009.
Qt is also interesting in that there is also an agreement in place with the KDE Foundation that ensures that the Qt Company will always offer the core parts of Qt under a "proper" open source license. If they choose to switch to one of these non-commercial licenses again, then KDE is entitled to release the source under a BSD license if they want
This is true now, but was not always the case.