Reby is a Ruby program that integrates with a eggdrop to allow you to script eggdrop in Ruby. It is _not_ a formal eggdrop module.
Although it's in beta (and could use more testers), it has been running on two eggdrops for a few months now with no catastrophic problems.
See the Reby website for some Reby scripts, such as a multi-engine websearch interface, calculation and conversion functionality, a word unscramble game, and more.