QtRuby... not yet.
With the announcement of the first Friday from the Pragmatic Programmers, which is Rapid GUI Development with QtRuby, I got really excited. I used QtRuby a little bit back when it was brand-spanking new, because I've used Qt more than once in the past (C++) and I think it is an excellent toolkit. I figured that this PDF book signalled that QtRuby was finally ready for prime time.
It is with great sadness that I report it is not so, at least not for me. It may well be solid enough for serious work. Since it is in Debian now, it may well be the easiest toolkit path on Debian-based Linux. It may have better documentation and a really cool PDF book from the Pragmatic Bookshelf. But it is nigh unto impossible to install on OS X. It claims to be able to, but the extremely complicated instructions fail to tell you what to do when this strange smoke thing fails to compile.
On the other hand, FxRuby is now much easier to get on OS X (and Linux) than it
has been in the past. Install Fox (with DarwinPorts on OS X or apt-get on
Debian), have rubygems (you do, don't you?), and type gem install fxruby.
Nice. It's not native OS X, but it's installable. I managed to get some
semblance of OS X nativity with Tk, but I seem to gravitate away from Tk for
some reason. I haven't tried ruby/gnome2 yet on OS X. I hear good things about
wxRuby, but I have found it also is impossible for mere mortals to install it
on OS X.
If I write a GUI app, I want it to have minimal requirements of installation by users. Right now I'd be happy to rely on DarwinPorts/Fink and gems to do the heavy lifting, but asking users to go through an excruciating manual compilation process that fails inexplicably just won't cut it.