Try Ruby/Gtk+ at http://ruby-gnome2.sourceforge.jp 

I've used it on Windows and Linux, and I'm pretty sure it can be
coaxed to run on OS X.

Bill

On Fri, 8 Oct 2004 04:08:51 +0900, MATTHEW REUBEN MARGOLIS
<mrmargolis / wisc.edu> wrote:
> I am currently designing a map editor for a game that I am writing in
> ruby.  I have never written anything along the lines of a map editor and
> was hoping that someone here could provide a few suggestions as to which
> graphical toolkit would best suit my needs.
> 
> I need to be able to display a large grid of 300 tiles, each of which
> can have a different picture that can change during execution.  I will
> need to be able to treat these tiles as individual buttons or have some
> other easy way to keep track of which tile the mouse is currently
> over/clicking on.  I will also need to be able to create a tool
> window(possibly floating) that will contain all the tools that you can
> use to operate on the tile grid.
> 
> Cross platform(Windows, Linux, Mac OS X compatibility would be optimal.
> 
> Thank you,
> Matthew Margolis
> 
>