Originally built as an add-on library extension of YUI by Jack Slocum April 15, 2007, Ext JS includes interoperability with jQuery and Prototype. Beginning with version 1.1, Ext JS retains no dependencies on external libraries, instead making their use optional.
Ruby on Rails, often called RoR or simply Rails, it's an open source framework for web applications written in Ruby
Ruby is a dynamic, reflective, object-oriented, general-purpose programming language
Django it's an open source framework for web applications development, written in Python