One of the big Rails philosophies that could help <i>any</i> platform is DRY: don't repeat yourself! ActiveRecord <i>et</i> <i>al</i> attempt to give you the reusable building blocks that will be required in most sites. And in that regard, I think it really does reduce developer time. There are also drop-in basics for user authentication, etc. A well-designed extension should be mostly portable to other apps. For example, while I don't know of a SAML plugin off the top of my head, building it once could get you to 90% for future cases. The sophistication seems less daunting when you work iteratively, tackling small chunks of functionality.<p>Having worked on both the J2EE and Rails stacks, I find Rails to be way more productive. But that productivity can be costly: many things feel like magic if you don't understand what the framework is doing. Looking back, J2EE development seems to require too much ceremony for too little reward.<p>The goal for web development should be to spend time on the application's <i>unique</i> properties, rather than on the generic ones that everyone must build. A framework like Rails attempts to get every project on the same page for component interaction, but allows you to step outside the mold if necessary.