I haven't chosen a cross-platform gui library yet, and I've decided to choose one based on which has the best documentation and the best community support. So does anybody have links to good tutorials, documentation pages, or community forums for their favorite cross-platform gui libraries?
It all depends on what you're doing, how you program, and whether the licence affects a particular project.
I like FLTK http://www.fltk.org a lot, but there isn't much in the way of a general graphics library. However it is fairly simple to extend the basic set of widgets to whatever you want.