Cross-platform
Bitweaver is a free and open source web application framework and content management system. (LGPL)
Cross-platform
CakePHP is a rapid development framework for PHP that provides an extensible architecture for developing, maintaining, and deploying applications. (MIT)
Cross-platform
Cappuccino is an open source framework that makes it easy to build desktop-caliber applications that run in a web browser. (LGPL)
Cross-platform
CodeIgniter is an open source Web Application Framework that helps you write kick-ass PHP programs. (Apache)
Cross-platform
Django is a high-level Python Web framework that encourages rapid development and clean, pragmatic design. (BSD)
Dojo

Cross-platform
The Dojo Toolkit is a modular open source JavaScript toolkit, designed to ease the rapid development of cross platform, JavaScript/Ajax based applications and web sites. (BSD)
Windows
DotNetNuke is an open source web application framework written in VB.NET for the ASP.NET framework. (BSD)
Cross-platform
Ext Core is a lightweight, high-performance cross-browser JavaScript library for building dynamic web pages. (MIT)
Linux, Windows, MAC OS X
Google Web Toolkit (GWT) is an open source set of tools that allows web developers to create and maintain complex JavaScript front-end applications in Java. (Apache)
Cross-platform
Grails is an open-source web application framework that leverages the Groovy language and complements Java Web development. (Apache)
Cross-platform
Horde is a PHP-based Web application framework. (LGPL)
Java
ICEfaces is an integrated Ajax application framework that enables Java EE application developers to easily create and deploy thin-client rich Internet applications (RIA) in pure Java. (MPL)
Cross-platform
JavaScriptMVC is a framework that brings methods to the madness of JavaScript development. (MIT)
Cross-platform
Jaws is a Framework and Content Management System for building dynamic web sites. (GPL)
Cross-platform
jQuery is a fast and concise JavaScript Library that simplifies HTML document traversing, event handling, animating, and Ajax interactions for rapid web development. (MIT)
Cross-platform
Madeam is a rapid application development PHP MVC Framework. It allows quick prototyping and deployment of web applications. (MIT)
Cross-platform
MMBase is a relational object mapping tool to create state of the art web applications. (MPL)
Cross-platform
MooTools is a compact, modular, Object-Oriented JavaScript framework designed for the intermediate to advanced JavaScript developer. (MIT)
Cross-platform
OpenLaszlo is an open source platform for creating zero-install web applications with the user interface capabilities of desktop client software. (CPL)
Java
pulse is a framework on top of the Servlet API providing easy to use and easy to extend patterns for creating browser based applications and websites. (GPL)
Cross-platform
The Qcodo Development Framework is an open-source PHP 5 framework that focuses on freeing developers from unnecessary tedious, mundane coding. (MIT)
Cross-platform
Ruby on Rails is a full-stack MVC framework for database-backed web applications that’s optimized for programmer happiness and sustainable productivity. (MIT)
Cross-platform
Symfony is a web application framework for PHP projects. (MIT)
Cross-platform
WAJAF is a Javascript framework working on the client browser side, and let you build complete applications without programming a single HTML or Javascript line. (GPL)
Cross-platform
Zend Framework is an open source, object-oriented web application framework implemented in PHP 5 and licensed under the New BSD License. (BSD)
Cross-platform
ZK is the most proven Ajax + Mobile framework designed to maximize enterprises operation efficiency and minimize the development cost. (GPL)
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