Twibot: A microframework for Twitter bots in Ruby / Ruby - cjohansen.no
http://www.cjohansen.no/en/ruby/twibot_a_microframework_for_twitter_bots_in_ruby

Twibot 0.1.1 hit the RubyForge gem server today. Inside is a microframework for writing Twitter bots in Ruby, using a DSL heavily inspired by Sinatra.