A simple Rails plugin which creates revisions of your model and comes with an equally simple HTML differ.
$ gem install revision-san
RevisionSan module into the model for which you'd like to keep revisions.
class Artist < ActiveRecord::Base include RevisionSan end
And create a migration to add the columns needed by Revision-San to your model:
add_column :artists, :revision, :integer, :default => 1 add_column :artists, :revision_parent_id, :integer, :default => nil add_index :artists, :revision_parent_id