…hmm, strange that you couldn’t open that website.
Actually, I took it from a Google search and was
able to open it.
There is more information about FXRuby here:
I subscribed to that mailing-list some time ago and received quite
a lot of helpful information from its very nice
expert members already.
You might also want to have a look at the documentation
of Fox itself.
More generally, I have always found Hal F.'s “The Ruby
Way” very illuminating with its many examples. The second
edition contains a chapter on FXRuby.