web2py

Free open source full-stack framework for rapid development of fast, scalable, secure and portable database-driven web-based applications. Written and programmable in Python. It Includes an SSL-enabled and streaming-capable web server, a relational database, a web-based integrated development environment and web-based management interface, a Database Abstraction Layer that writes SQL in real time, internationalization support, multiple authentication methods, role based access control, an error logging and ticketing system, multiple caching methods for scalability, the jQuery library for AJAX and effects, and a scaffolding application to jumpstart development.

web2py was inspired by Ruby on Rails and, as Rails, it focuses on rapid development and follows a Model View Controller design. web2py differs from Rails because it is based on Python (thus it is faster and more scalable), because it provides a comprehensive web-based administrative interface (thus there is no need to ever type shell commands unless you wish), includes libraries to handle more protocols (for example XML-RPC and RSS feeds), and can run on the Google App Engine.

web2py was also inspired by Django and, as Django, it has the ability to generate forms from database tables and it includes an extensive set of validators. web2py differs from Django because it is more compact, easier to learn and does not have any project-level configuration files. web2py comes in source code version (for any Operating System that runs Python) and in binary versions for OSX and Windows. web2py does not need to be installed.