What is "pyjs"

Pyjs (formerly Pyjamas before May 2012), is a rich Internet application framework for developing client-side web and desktop applications in Python. The resulting applications can be run in a web browser or as standalone desktop application.

It contains a stand-alone Python-to- JavaScript compiler, an Ajax framework and widget toolkit, and through use of these components, developers can write comprehensive applications, to run in all major web browsers, without writing any JavaScript. Pyjs is a port of Google Web Toolkit (GWT) from Java to Python.