Oh. That was not at all what I expected from the title... I thought it would be about either the new QML compiler, or the desktop-advertising library. (Though the domain should of course have been a giveaway. Didn't notice that at first.)
I figured it was something about cardiac health, where the "Q-T interval" between two EKG landmarks is an important diagnostic indicator. I also didn't pay much attention to the domain.
You aren't the only one haha, I work with Qt every day and this was my first thought.