Pyjs is a Python Rich Internet Application (RIA) Development Platform for both Web and Desktop.
It contains a Python-to-Javascript compiler, an AJAX framework and a Widget Set API. Pyjs started life as a Python port of Google Web Toolkit (GWT), the Java-to-Javascript compiler. Read the FAQ.
Pyjs Desktop is the Desktop version of Pyjs
Pyjs Desktop allows the exact same python application source code to be executed as a Desktop application. Since Pyjs 0.6 Pyjs Desktop has been integrated into the Pyjs Release. Pyjs Desktop is conceptually equivalent to Adobe AIR.