OK, I just checked on the Qt website. It looks like they do have a free version available under the LGPL license. But, if you ever decide you want to sell one of your programs with Qt, you'll have the pay the 4K licensing fee.
WxWidgets has a lot of features, maybe that's what you mean by complex?
If you decide to try out WxWidgets, use the "WxPack," not the "real" version where you have to build the library yourself.
http://wxpack.sourceforge.net/