Rails' main strength is that the framework itself provides really good sensible defaults and organises itself (config, environments, routes, models, controllers

Rails' main strength is that the framework itself provides really good sensible defaults and organises itself (config, environments, routes, models, controllers, helpers, tests) in an easily-extendable manner. I can usually familiarise myself with an app in a matter of minutes and can get a working prototype up and running within an hour. All this makes me really productive, and writing Ruby is a joy.