Dynamic Form is a Python request abstraction library that lets you write one request handler that will run on multiple Python web frameworks (such as Django and Google's AppEngine). This allows you to create pages and apps once and use them on multiple projects without concern about which framework is being used. Additionally DynamicForm makes AJAX easy. Simply adding nested request classes allows you to define AJAX handlers that can easily be refreshed both sever-side and client-side.
For more info see: http://www.dynamicform.org/