Hi everyone,

Thanks for the suggestions. There's a little more detail I've put in  
the other post, 'Oh the pain!', but I've spent the last half a day  
playing with JRuby and think this may be the way to go.

Looks like a brilliant idea and I can use swing for the gui (I'm  
quite familiar with swing, so no new learning here).

On a related note, anyone got anti-aliasing working with JRuby? My  
code (canvas is a JPanel):
canvas.getGraphics.setRenderingHint(RenderingHints::KEY_ANTIALIASING,  
RenderingHints::VALUE_ANTIALIAS_ON)
runs with no errors, draws what I expect, but no anti_aliasing. I'm  
pretty sure this is due to my not understanding properly the change  
in syntax from Java to Ruby.
[I've also posted this to the JRuby list (user / jruby.codehaus.org).  
but don't know how popular it is.]

Cheers,
Dave