You might want to search the archives for recent discussions on this list about GUI frameworks. wxWidgets was discussed in detail, and there was even talk about a collaboration between wxWidgets and Boost developers. However, the conensus was that wxWidgets was decidedly unmodern C++.
I will do that. I do want to clarify though as it seems there may have been a misunderstanding as to what I'm interested in. I'm not really looking for a gui framework or necessarily cross platform capability. I'm mainly interested in studying techniques used in a full blown gui application that is designed using modern techniques. Preferably OSX since that's what i use, but not necessarily that either. If there's a well designed and implemented application for another platform I would like to study that code as well. Regards, Matthew