Erik Veenstra wrote:

>>I've used RubyScript2Exe to bundle up my entry for the Ludum
>>Dare 48 hour game development contest.
> 
> Which GUI toolkit did you use?

None at all. I used the ruby-gosu gaming library which handles creating 
the window with the graphics surface. See 
http://www.raschke.de/julian/gosu/ for more information on ruby-gosu.