Kurt Stephens

Cool new Ruby gem Aquarium – AOP framework for Ruby:

http://aquarium.rubyforge.org

Discussion of AOP, Rails and GOF design patterns:

http://cfis.savagexi.com/articles/2007/09/05/rails-unusual-architecture

Not really AOP or Decorator because it occurs at the M1 (class, module) and not the M0 (object) meta-modeling layer.