I've done quite a bit of research on Ruby GUI design, and it appears to be the one area where Ruby tends to be behind the curve. I've explored the options of MonkeyBars, wxRuby, fxRuby, Shoes, etc. and was just wanted to get some input from the Ruby community.

While they're definitely usable, the development on each seems to have fallen off. There is not a great deal of useful documentation or user bases that I could find on any (minus the fxRuby book). I'm just looking to make a simple GUI, so I don't really want to spend hundreds of hours learning the intricacies of the more complex tools or attempt to use something that is no longer even being developed (Shoes is the type of application I'm looking for, but it's extremely buggy and not being actively developed.) Out of all of the options, which would you guys recommend as being the quickest to pick up and that still has some sort of development base?

Thanks!