There’s a good tutorial on MacZealots.com about installing Rails on Tiger. Rails is a development framework built on top of the Ruby programming language, a scripting language similar to Perl or PHP but object-oriented. The Rails framework brings the model-view-controller paradigm to web development. While not the first or only language to do that, the fact that it brings things like AJAX to the table along with some pretty good data model generation functionality makes it worth considering in any new web development. The best endorsement, though, is that all of the 37Signals applications are built using Rails. Those are some great web applications with some excellent UIs.