Pyjamas desktop is the desktop version of pyjamas, the web widget application framework.

pyjamas is typically used for the development of "web 2.0" rias, where the application can be almost exclusively written in python, instead of javascript, yet compiled to run in the user's browser.

the desktop version of pyjamas takes the original python application (which, in the browser version, is put through a javascript compiler), and executes it directly, through the standard python interpreter, unmodified. the pyjamas infrastructure then uses xulrunner as the browser engine, to render the application's widgets.