Q: How about a ruby script that converts (a subset of) UML into a rails-scaffold-application (w/ database, models, and controllers).
A: Converting UML to X always sound good in theory, but in practice it always sucks as it’s near impossible to know up front what the right(UML) domain model will be for your app. First time perfect is never realistic. It’s better to “grow” your application through good agile practices. Besides that, most UML diagrams are impossible to comprehend and they tend to become useless very fast during development because of ever changing requirements.