FoxGUIb
From eqqon
FoxGUIb makes it easy to create user interfaces with FXRuby. It is an interactive GUI builder and code generator. It is the perfect tool for newbies to find out how the Fox-Toolkit works without reading the API docs. It is of course also a tool for professionals because it saves you a lot of typing and "build-cycles" when tweaking user interface look-and-feel.
Download foxGUIb at http://fox-tool.rubyforge.org