Google's Web Toolkit (GWT) lets you develop a Rich Internet Application(RIA) with Ajax, entirely in Java code. You can use the rich Java toolset(IDEs, refactoring, code completion, debuggers, and so on) to developapplications that can be deployed on all major Web browsers. With GWTyou can write applications that behave like desktop applications butrun in the browser. Pyjamas, a GWT port, is a tool and framework fordeveloping Ajax applications in Python.
WebKit, XUL, and their ilk bring modern flair to desktop applications.Pyjamas brings WebKit to Python developers. With Webkit, Pyjamas becomesa cross-browser and cross-platform set of GUI widgets. You can developwidgets that will run anywhere WebKit and XUL run. The Pyjamas API-basedapplication can live anywhere GWT applications would live. Plus, Pyjamaslets you write desktop applications built on top of WebKit and XUL.This is preferable to building applications on top of Qt or GTK becauseWebKit supports CSS, and it is used in many other places for reliablerendering (iPhone, Safari, Android, and so on).
With Pyjamas you create containers, then add widgets to the containers.The widgets can be labels, text fields, buttons, and so forth. Widgets,like buttons, have event handlers so you can listen for click eventsfrom the button..."