RubyForge Project Page
Unfortunately RAV hasn't been updated since the days of Rails 1.1. If you're looking for a way to visualize your Rails apps, you would do well to investigate Railroad, a more up-to-date project with similar goals.
(cd vendor/plugins && svn co svn://rubyforge.org/var/svn/rav/stable rav)
rake visualize [FILENAME=filename] [MODELS=no] [CONTROLLERS=no]
FILENAME specifies where you want the diagram. Default is
RAILS_ROOT. RAV guesses the format to use from the
filename. You may use any format that Graphviz supports, including
PNG, SVG, GIF, JPG, PS and even (no joke) VRML.
By default the diagram includes both models and controllers, but you may disable either with MODELS=no and CONTROLLERS=no.
Copyright (C) 2006 Christoffer Sawicki and Phil Hagelberg