RailsにおけるEngineとかComponentとか

たぶん、Railsにとって本質的な話なので。

Why engines and components are not evil but distracting
http://weblog.rubyonrails.com/articles/2005/11/11/why-engines-and-components-are-not-evil-but-distracting

The case against high-level components
http://www.loudthinking.com/arc/000407.html

Beyond boilerplates: Structure generation
http://www.loudthinking.com/arc/000533.html

参考:Rails Engine
http://rails-engines.rubyforge.org/

Oh Good Lord: What have we done?
http://rails-engines.rubyforge.org/wiki/wiki.pl?OhGodWhatHaveWeDone