Ruby on Rails

+ Ruby on Rails for the rest of us provides a nice overview.

Rails has three major goals:

* Simplicity: Developing applications should be easier, since many data-driven sites share a common set of parameters. For example, instead of focusing on writing code that will connect your application to a database, Rails handles all of that for you, thus allowing you to spend that time working with your actual application logic.
* Logical: Rails follows the Model-View-Controller (MVC) architecture for application development, which allows for a logical separation of your application logic, business rules, and user views. By keeping these things segregated, it not only makes initial development easy, it also makes updates and maintenance to your system quicker.
* Happiness: Since developing using Ruby on Rails strives to be simple and logical, it will in turn lead to a happy (and more productive) developer.

One my new webhaunts, Twitter.com, is built off Rails.