In one of my classes, we used Ruby and Gtk, but some issues popped up. The most obvious is using a block to do GUI update stuff and the like, from another thread. Things die. Puppies are killed. I found this post on Ruby Forum which fixed the problem. Relevant code. Basically, you call the Gtk.init_thread_protect method first when you start things up, then, whenever you need to do GUI update stuff, just wrap it in a Gtk.thread_protect {} block. …

If you go download the ruby-gnome stuff, and GTK fails to compile, it's easy to fix. It whines about some defines, and you can just comment out the block that's causing the problem.