I'm concerned about the state of GUI toolkits for Ruby when in comes to
installation requirements, particularly under Mac OS X.  I'm think about the
case where we want to create a Ruby-based GUI application for non-developers to
use.

I recently went through the steps to get Tk working with Ruby under Mac OS X. 
It was fairly complicated.  After all that work I found that GUIs I had created
under Windows didn't look very good on Mac OS X.  I then decided to try FOX. 
That required downloading the X11 software from Apple.  I installed that and
then found that I didn't automatically get the X11 library files that are
needed in order to build FOX.  Maybe I'll get this figured out eventually.

The bottom line is that even if you take the time to write a great GUI app.
using Ruby, your audience of potential users will likely be quite small. 
Installing Ruby is easy enough, but setting up a GUI toolkit is prohibitively
complex for a non-developer.  Compare this to Java.  Install the Java Runtime
Environment or use Java Web Start and Swing is available.

One answer is to create web apps instead.  That's not appropriate for every
application though.

Do others think this is an issue?

--
R. Mark Volkmann
Partner, Object Computing, Inc.