http://ec2-50-19-46-70.compute-1.amazonaws.com/apps/demo2 Above is a screenshot of an online class hierarchy browser for the ExtJs 4.0 JavaScript library. It was built in about three hours using Sencha’s new Designer 2.0 GUI builder. There are only a limited number of “good” fundamental ideas in computer programming and the same ideas keep get “rediscovered” and coming back into fashion. This seem