GTK-- vs. QT

spirality asks: "The company I work for is getting ready to decide on a GUI Toolkit for our Computational Modeling Toolkit (CoMeT, www.cometsolutions.com). We would like C++ compatibility and ports to various Unices and Win32 platforms. Not supprisingly we've come up with two choices, GTK-- and QT. I've attempted to compare the two by doing alot of web surfing and searching, but I've come up with things that are consistently one or more years old. So, the question I pose is what are the (dis)advatages of GTK-- and QT, and why would I choose one of these toolkits over the other? Overall functionality, momentum for future growth, ease of use, licensing, and pretty much anything else is relevant to our decision." With QT now at version 3.0 and GTK now in the 1.2.x revisions, maybe it's time to give the two libraries some fair comparison and discuss the new features, advantages, and disadvantages of each?