Visual Ruby
Create GUIs with Ruby.
Visualruby was designed specifically for rubyists who want to add a GUI to their ruby scripts. It enormously simplifies the process of adding GTK+ windows to your applications. Visualruby is completely integrated with the glade interface designer, so you only need to click on a ruby file to edit its widgets using glade.
The editor has a “Run” button to execute your script, and if an error occurs, the editor will automatically jump to the spot in your code that caused the error. Also, you can create a .gemspec file, compile your gem, install your gem, or push, yank or uninstall your gem with just one mouse-click.