This document discusses how Rails may not be the best tool for rapid prototyping and suggests alternatives that are more lightweight and collaborative. It introduces Serve, an alternative to Rails that uses a simple folder structure and views to quickly prototype ideas without models, controllers or routing. Serve works with popular front-end tools and libraries and can deploy to Heroku. The document argues that prototyping tools should empower all team members, including front-end developers, and that Rack middleware like Rack::Cascade allows reusing mockups and wireframes in a Rails app.