Open Source Web Frameworks written in Java

• Anvil - Anvil is a Java based server environment and object oriented programming language with templating support, being especially well-suited to for web applications.
      
• Barracuda - Barracuda is an Open-Source Presentation Framework (LGPL) designed to make it easier to build web apps by providing a simple yet powerful Server-Side Component Model that makes it easy to manipulate DOM structures using proven MVC patterns like you would find in Swing. With this newest release, you can now use Jivan in addition to XMLC to load and render your DOM templates.
  
  In addition, Barracuda supports Model 2 Flow Control handling with a sophisticated Server-Side Event Model. Barracuda also provides a Form Mapping & Validation package to automatically map forms to objects and validate them, along with integrated XMLC Localization support! Barracuda offers a number of utility classes in a library called Plankton
  
      
• Chrysalis - Chrysalis is a Java web development framework. It has a different focus from most Model-View-Controller (MVC) web frameworks. Chrysalis controllers resemble normal Java classes with multiple methods. Client request URLs are mapped to each controller method.
  
  The typical MVC framework is founded on one basic insight: that Java servlets can be treated as an event handler for the submit button of HTML forms. This makes servlets analogous to the controller in the MVC pattern, equivalent to the Listener classes used in Java GUIs.
  
      
• DWR - AJAX is an approach to writing web pages that improves a web sites appeal and usability. It enhances user interaction by targeting updates from the server to specific areas of the web page, known as n-page replacement. It allows information to be changed without long delays or frustrating page refreshes.
  
  DWR (Direct Web Remoting) is easy AJAX for Java. It reduces development time and the likelihood of errors by providing commonly used functions and removing almost all of the repetitive code normally associated with highly interactive web sites
  
      
• Echo - Echo is a framework for developing object-oriented, event-driven Web applications. Echo removes the developer from having to think in terms of "page-based" applications and enables him/her to develop applications using the conventional object-oriented and event-driven paradigm for user interface development. Knowledge of HTML, HTTP, and JavaScript is not required. Echo is open-source software distributed under the terms of the Mozilla Public License or the GNU LGPL License.
  
  
      
• Jaffa - Jaffa v2.1 is a not only a maintenance release, but also introduces many new features. In conjunction with this release new versions of the sub-projects (JaffaBaseline, JaffaComponents and Example1) have been updated to make use of these new features.
  
  The full details of what has been added since v2.0 are available in the release notes, but the most notable ones are
  
  Native Tomcat 5.0 support, including jsp precompiling
  Full relational integrity supported in the v1.1 domain pattern
  New bean moulding framework for updating and retrieving graphs of domain objects, idea for complex web services
  Two new database schema importers, we can now import domain models from the database schema, ErWin CASE tool as well as Uniface
  
      
• JAT - JAT is a flexible Java base-framework which can be easily extended to improve projects start-up time. JAT allows to build Web applications (J2EE) or standalone application (server, batch, etc.). JAT supplies the main basic functionalities of any Java application, such as:
  
  * High Business Object abstraction
  * Integration facilities (provided for DBMS, LDAP and open to any software product)
  * Authentication and user privileges management
  * MVC pattern implementation (with privileges management and page flow control)
  * HTML layout structure management (header, footer, menu, etc.)
  * HTML dynamic contents and facilities (form, report, paging)
  * Logging feautures
  * Help on-line utility
  * High configuration of all described functionalities
  * Administration and configuration GUI
      
• JOSSO - JOSSO, or Java Open Single Sign-On, is an open source J2EE-based SSO infrastructure aimed to provide a solution for centralized platform neutral user authentication.
  
  JOSSO uses web services for asserting user identity, allowing the integration of non-Java applications (i.e: PHP, Microsoft ASP, etc.) to the Single Sign-On Service using the SOAP over HTTP protocol.
  
  JOSSO comes with a Reverse Proxy component that can be used to create n-tier Single Sign-On configurations.
  
  
      
• JSPWidget - It solves your JSP long-lasting pain - code/UI mixed spaghetti code. With JSPWidget GUI Widgets , you can write event handler to handle the event fired by the GUI widget . Access and manipulate GUI widget completely in code without mix them together and the view state of GUI widgets are automatically retained. Plesae see design goal for detailed description.
  
  In addition to GUI widgets, JSPWidget contains a set of Validation Widgets for you to validate input field declarely without even writing a signle line of code.
  
  For the sake of completeness, JSPWidget also contains a set of Util Widgets and SQL Widgets to assist you in web developing. You are free to using any other tag library that has similar functionalities. You can mix your other favarite tag library with JSPWidget
  
      
• Jucas - Struts (like other Model II frameworks) have brought the separation between View and Model and Controler to the web programming. On the other hand recent frameworks like Java Server Faces (JSF) or ASP.NET try to provide the advantages of object (component) orientated GUI-Design known from fat-client apis like Swing or Visual Basic (stateful objects, event-mechanismus).
  
  Jucas combines both approaches. Stateful components (JavaBeans) are used to represent the model and the controller and templates use this components to render the view.
  
  
      
• Maverick - Maverick is a Model-View-Controller (aka Model 2) framework for web publishing using Java and J2EE. It is a minimalist framework which focuses solely on MVC logic, allowing you to generate presentation using a variety of templating and transformation technologies.
  
  In principle it combines the best features of Struts, WebWork, and Cocoon2, however:
  
  Maverick is simple to use - this is a minimalist framework that anyone can understand easily. This is not a kitchen sink framework that tries to provide everything you need to build a web application; there are plenty of great database connection pools, application servers, validation frameworks, templating languages, etc already out there.
  
      
• Millstone - Millstone is a user interface library for development of networked Java applications. It provides a terminal independent component model that can be adapted to different terminal types and user interface themes.
  
  The development model of Millstone is closely related to traditional client side UI development: it has a continuous application lifecycle and an extensive event model. The Millstone library also provides an interface for directly connecting UI components to business logic and data storage.
  
  
      
• MyFaces - JavaServer(tm) Faces is a new and upcoming web application framework that accomplishes the MVC paradigm. It is comparable to the well-known Struts Framework but has features and concepts that are beyond those of Struts.
  Look at Sun JavaServer(tm) Page to learn more about the Java Specification Request 127 and to download the specification. They also provide a useful Tutorial there.
  
  JSFCentral is also a good place for more JSF information and resources.
  
  
      
• RIFE - RIFE offers an alternative approach to web application development and design. It builds upon the Java platform, but offers all required tools and APIs to implement and perform all common website related tasks in a fast, intuitive and consistent manner. RIFE has been designed for perfect separation of tasks during a development cycle. Every developer, dba and designer only has to focus on his own tasks. At any moment the work can be effortlessly integrated with the work of the rest of the team. This results in a loosely coupled and very robust system. One can make incremental improvements with little or no risk of unwanted side-effects elsewhere in the system. RIFE is composed out of a large collection of modular parts, which include:
  
  * web application engine,
  * integrated web continuations,
  * customizable multi-format template engine (html, xml, sql, java, txt, ...)
  * support for template content transforming through for example XSLT,
  * authentication framework,
  * database query builders,
  * simple persistance layer,
  * fault-tolerant JDBC wrappers and connection pooling,
  * web-oriented database utilities,
  * central data repository,
  * cron-like scheduler,
  * configuration framework. The central part is the engine which formalizes all aspects of dynamic web development. It graciously solves all doubt, confusion and maintenance problems of HTTP statelessness and liberal CGI interface
      
• SOFIA - SOFIA is the Salmon Open Framework for Internet Applications. It is open source code that you can download for free and put to work today.
  With SOFIA, developers can rapidly build applications using JSP Servlet technology. SOFIA accomplishes this by integrating best of breed development tools design tools like Dreamweaver and integrated development environments like IntelliJ and Eclipse. SOFIA unrivaled GUI development significantly improves a developers experience. Using Dreamweaver within SOFIA, for example, visual portions of an application can be painted instead of hand-coded.
  
  
  
      
• Struts - The core of the Struts framework is a flexible control layer based on standard technologies like Java Servlets, JavaBeans, ResourceBundles, and XML, as well as various Jakarta Commons packages. Struts encourages application architectures based on the Model 2 approach, a variation of the classic Model-View-Controller (MVC) design paradigm.
  
  Struts provides its own Controller component and integrates with other technologies to provide the Model and the View. For the Model, Struts can interact with standard data access technologies, like JDBC and EJB, as well as most any third-party packages, like Hibernate, iBATIS, or Object Relational Bridge. For the View, Struts works well with JavaServer Pages, including JSTL and JSF, as well as Velocity Templates, XSLT, and other presentation systems.
  
      
• Swinglets - In fact Swinglets actually uses the Swing models (e.g. TableModel). This means you can take your existing models and start working with Servlets straight away. It just about as close to a standard as you can get without it actually coming from Sun themselves.
  
  
      
• SwingWeb - Swingweb is an implementation of AWT toolkit that enables AWT/Swing application to be operating inside a web container and presented as a web application to the web browser, purely in HTML/CSS/javascript. There no code conversion required for the swing application to run in the SwingWeb environment. Some of the features of SwingWeb include the following:
  
  * Support web-environment with multiple concurrent application sessions
  * Component-oriented architecture that allows developer to enable existing swing component to web environment easily
  * Support common AWT/Swing components in java.awt.
  * and javax.swing.
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  * Support all component layouts in jdk
  * Highly configurable use of jxp template for component presentation
      
• Tapestry - Tapestry is an open-source framework for creating dynamic, robust, highly scalable web applications in Java. Tapestry complements and builds upon the standard Java Servlet API, and so it works in any servlet container or application server.
  
  Tapestry divides a web application into a set of pages, each constructed from components. This provides a consistent structure, allowing the Tapestry framework to assume responsibility for key concerns such as URL construction and dispatch, persistent state storage on the client or on the server, user input validation, localization/internationalization, and exception reporting. Developing Tapestry applications involves creating HTML templates using plain HTML, and combining the templates with small amounts of Java code using (optional) XML descriptor files. In Tapestry, you create your application in terms of objects, and the methods and properties of those objects -- and specifically not in terms of URLs and query parameters. Tapestry brings true object oriented development to Java web applications.
  
  
      
• Turbine - Turbine is a servlet based framework that allows experienced Java developers to quickly build web applications. Turbine allows you to use personalize the web sites and to use user logins to restrict access to parts of your application.
  
  Turbine is a matured and well established framework that is used as the base of many other projects (like e.g. the excellent Jetspeed 1 Portals framework.
  
  
      
• Verge - This is a write up of a Java developers experience with Apple Mac, OS X and Java. An interesting read that covers his 4 week journey into the world of Apple and what Apple had to say to the Java community. This story also contains links to various blogs and information regarding Java 5.0 and Mac OS X.
  
  
      
• VRaptor - VRaptor is a Model-View-Controller web application framework that tries to implement the best features from the following state of art MVC frameworks: WebWork 2, Spring Framework and Struts. It is highly focused on the Inversion of Control principles, using the Constructor Injection philosophy brought by the PicoContainer.
  
  This framework uses a more imperative approach, instead of having lots of xml files to configure lifecycle and other properties. Most of the settings go inside plain Java objects, so the team knows exactly what is going on, and where. A big effort is done to avoid too much magic .
  
  
      
• WebOnSwing - WebOnSwing is a revolutionary multiple environment application framework that allows you to create web applications in the same way you develope a desktop one. You dont need to use JSP files, special tags, XML files, requests, posts, etc. Everything is Java and pure HTML files that comes directly from the graphic designer.
  WebOnSwing is an open source project distributed under LGPL license.
  
  This framework constructs and handles html pages with Swing components, allowing to use MVC architecture and all the facilities provided by Swing in the web.
  
  
      
• WebWork - WebWork is a Java web-application development framework. It is built specifically with developer productivity and code simplicity in mind. WebWork is built on top of XWork, which provides a generic command pattern framework as well as an Inversion of Control container. In addition to these features, WebWork provides robust support for building reusable UI templates, such as form controls, UI themes, internationalization, dynamic form parameter mapping to JavaBeans, robust client and server side validation, and much more.
      
• Wicket - Wicket is a Java web application framework that takes simplicity, separation of concerns and ease of development to a whole new level. Wicket pages can be mocked up, previewed and later revised using standard WYSIWYG HTML design tools. Dynamic content processing and form handling is all handled in Java code using a Swing-like component model backed by POJO data beans that can easily be persisted with Hibernate