Cocoa for Windows
Well, not exactly.
I wasn't real excited about the Qt toolset - I got something working but the Mac interface doesn't quite work yet. Something as simple as selecting and copying text started to misbehave in their designer tool. The widgets themselves seem to work quite nicely but after a bit of thought, I decided to try my own hand at writing a small GUI framework for my Window's ports.
This morning I finished some C++ to open a MainWindow along with a SplitView child. It isn't Objective-C so it isn't perfect but indeed, I am including things like delegates and where approrpriate, opting to conform to Objective-C interfaces and general design decisions. It's turning out to be quite fun. Once I finish a rudimentary framework, I should be closer to completing the Windows port of my new idea!