» Kazehakase...ruby in your browser?!! +
I just came across a project called Kazehakase. It is a web-browser based on Gecko (the Mozilla/Firefox HTML rendering engine). Big deal, you say. There are already Galeon and Epiphany and so forth. But I ask you, do any of those browsers have a ruby prompt sandbox (with autocompletion!) built in? No? Didn't think so. Well, kazehakase does!
The docs are mainly in Japanese and the wiki and mailing list are subject to spammage, but you can always check out the source of ext/ruby/kz/ruby-dialog.rb to see what's going on behind the scenes.