>>
> Qt 4 Ruby works on Windows and Linux for sure. I don't know about  
> Macs, though. I think most Mac users prefer native Mac GUIs anyhow,  
> and there is one for Ruby that has a very good reputation. I don't  
> have a Mac, so I've forgotten the name.

I'm using Qt4 QtRuby on the Mac and Linux wonderfully.  I've started  
diving into an attempt to build it on Windows, but honestly, using  
Windows for software development is very frustrating for me.   
However, it certainly is feasible to build and once someone does and  
they share their library or routine for building it, we can safely  
say it's supported there as well.

Caleb