Drools is an enhanced Rules Engine implementation, ReteOO, based on Charles Forgy's Rete algorithm tailored for the Java language. More importantly, Drools provides for Declarative Programming and is flexible enough to match the semantics of your problem domain with Domain Specific Languages.

Jetty is an open-source, standards-based, full-featured web server implemented entirely in Java. It is released under the Apache 2.0 licence and is therefore free for commercial use and distribution. First created in 1995, Jetty has benefitted from input from a vast user community and consistent and focused development by a stable core of lead developers. There are many more examples of Jetty in action on the "Jetty Powered Page":http://docs.codehaus.org/display/JETTY/Jetty+Powered that has selections from among the tens of thousands of production Jetty instances. However, as Jetty aims to be as unobtrusive as possible, countless websites and products are based around Jetty, but Jetty is invisible!

JParsec allows declarative parser construction in native Java. Operator precedence grammar, dynamic grammar are particularly easy in JParsec.

Ruby extension providing bindings back to an in-processes hosted JVM. Java classes are exposed through Ruby semantics.

Codehaus XFire is a next-generation java SOAP framework. Codehaus XFire makes service oriented development approachable through its easy to use API and support for standards. It is also highly performant since it is built on a low memory StAX based model.

PicoContainer is a lightweight and highly embeddable container for components that honour Dependency Injection. Dependency Injection is a type of Inversion of Control.

StAX is a standard XML processing API that allows you to stream XML data from and to your application. This StAX implementation is the standard pull parser implementation for JSR-173 specification.

XStream is a simple library to serialize objects to XML and back again. Features: Ease of use, no mappings, performance, clean XML, no modifications to classes, integration with XML libraries, full object graph support, customizable conversion strategies.

Castor is an open source data binding framework for Java. It's the shortest path between Java objects, XML and relational tables. Castor provides Java-to-XML binding, Java-to-relational persistence, and more.

The Classworlds project.

The Plexus project provides a full software stack for creating and executing software projects. Founded on the Plexus container, applications can utilise component-oriented programming to build modular, reusable components that can easily be assembled and reused.

Woodstox is a high-performance XML processor. It implements StAX (Streaming Api for Xml, JSR-173), and supports XML 1.0 and 1.1(including full DTD validation), XML Namespaces 1.0 and 1.1. In addition to core Stax 1.0 API, Woodstox has extended API for pluggable bi-directional validation, both using DTDs (in-built), and external validation modules (for Relax NG, W3C Schema, using Sun MSV). With version 3.2 Woodstox also implements SAX API for improved interoperability.

Janino is a compiler that reads a Java expression, block, class body, source file or a set of source files, and generates Java bytecode that is loaded and executed directly. Janino is not intended to be a development tool, but an embedded compiler for run-time compilation purposes, e.g. expression evaluators or "server pages" engines like JSP. Janino can also be used for static code analysis

A collection of Java-based econometrics tools

This plugin can be used to efficiently monitor a given instance of Confluence for any updates to page, users, comments etc.

GeoServer is an Open Source server that connects your information to the Geospatial Web. With GeoServer you can publish and edit data using open standards. Your information is made available in a large variety of formats as maps/images or actual geospatial data. GeoServer's transactional capabilities offer robust support for shared editing. GeoServer's focus is ease of use and support for standards, in order to serve as 'glue' for the geospatial web, connecting from legacy databases to many diverse clients. GeoServer supports WFS-T and WMS open protocols from the OGC to produce JPEG, PNG, SVG, KML/KMZ, GML, PDF, Shapefiles and more.

The GeoTracing team is busy moving in from www.geotracing.com.

JRuby is an alternate implementation of the Ruby programming language.

A high performance, lightweight, StAX based SOAP framework with pluggable

Yan Container mandates no contract between container and your components. Design your IoC components at will and forget about what's so called "container". Yan is able to manage java component designed in any fashion (be it Java Bean, Constructor, Static Factory, Abstract Factory, Singleton, Object Pool or any combination.) _declaratively_. All features in Yan are provided with no intrusion needed. You will never end up being locked up in Yan as you might be with the funny BlahBlahAware interfaces. And there will be nothing that you can do in Java but can't in Yan.

A set of java tools that allow for the monitoring and management of data

XPlanner is a project planning and tracking tool for eXtreme Programming (XP) teams. If you are not familiar with XP software development practices, the links page contains pointers to relevant resources. To summarize the XP planning process, the customers pick the features to be added (user stories) to each development iteration (typically, one to three weeks in duration). The developers estimate the effort to complete the stories either at the story level or by decomposing the story into tasks and estimating those. Information about team development velocity from the previous iteration is used to estimate if the team can complete the stories proposed by the customer. If the team appears to be overcommitted, the set of stories are renegotiated with the customer. The XPlanner tool was created to support this process and address issues experienced in a long-term real-life XP project.

maven-proxy is a lightweight servlet engine that sits on your main server and imitates ibiblio (for instance). When it gets a request for a jar it doesn't have, it gets the jar from the upstream servers and stores it into it's cache before returning it to the requester.

Multi-threaded/Multi-JVM System Testing Extension for JUnit.

Modello generates code from a simple model format. Based on a plugin architecture, various types of code and descriptors can be generated from the single model, including Java POJOs, XML marshallers/unmarshallers, DTD and XSD generators, persistence generators and documentation generators.

Berkano aims to provide components which can ease the development of web applications. One of the targets is the user management area, covering the basic user data model up to password recovery strategies, etc...

JayWalker is an open-source software analysis tool which can be used either at build or deployment time to interrogate a Java application's compiled artifacts and generates static and interactive graphical reports from it. In turn, a software professional can interpret and use these reports to improve software quality and to understand the current state of the software application in question.

Jencks is a lightweight JCA container which is easy to deploy inside Spring to provide inbound and outbound messaging using APIs like JMS, JAX-RPC, JBI and JCA CCI as well as providing an XA based pooling mechanism for JDBC and easy integration of Geronimo's TransactionManager with Spring.

Lingo is a lightweight POJO based remoting and messaging library based on Spring's Remoting which extends it to support JMS. Lingo can support a wide range of message exchange patterns including both synchronous and asynchronous message exchange. Lingo is an ideal technology to cluster your POJO services to achieve load balancing across many servers and automatic failover. Lingo is high performance and works great in server centric environments as it can work with JCA to cleanly integrate with thread, connection and session pooling as well as handing of transactions, retry and exception handling.

Bla bla.

Integration of Maven1 and Maven2 into popular Java IDEs, like Eclipse, Netbeans, IDEA or Jbuilder. Maven2 support currently only for Netbeans.

Not slated until Java 7.0, Java developers will be able to find methods by parameter names. This tool adds it back for Java 1.4 and onwards

jMock is a library for testing Java code using mock objects. Mock objects help you design and test the interactions between the objects in your programs. The jMock package: makes it quick and easy to define mock objects, so you don't break the rhythm of programming. lets you define flexible constraints over object interactions, reducing the brittleness of your tests. is easy to extend.

QDox is a high speed, small footprint parser for extracting class/interface/method definitions from source files complete with JavaDoc @tags. It is designed to be used by active code generators or documentation tools.

A tool for monitoring ANT build file execution.

Terminal based log tools written in java. Replacements for grep, tail, less with understanding of typical java log files.

The Milyn Project is focused on providing tools for performing Data Analysis and Transformation (both XML and non-XML). The primary component in the Milyn Project is "Smooks". Smooks is a tool for performing "Fragment Based" data Analysis and Transformation, with support for data/message "Profiles".

Using English, write down some stories. Suggest some scenarios to fully illustrate the stories. Split the scenarios into sequences of contexts, events and outcomes. Reuse them to describe and illustrate the different behaviours of your system. Run the stories. If you need some code to make the system behave as it should, write down the behaviour of the code. Run the behaviours. If the code isn't doing what it should, change it so that it behaves. It's like testing, but without the tests.

XHarness is a system test harness for Apache Ant 1.6.x. It allows people to describe their product/system tests in the form of XML as part of an ant build file, describing the tasks and processes that comprise the test cases and what their expected behaviour is. It has powerful process management capabilities, that extend the existing Ant process tasks (exec, java) to allow asynchronous execution of java and native processes (e.g. for client-server tests), synchronization between multiple processes and complex assertions on process and task output (stdout/stderr, file output, coupled with timeouts, etc.). It also has the concept of a "service" that encapsulates the necessary infrastructure for testcases to run (e.g. a Webserver) and adds a number of other useful tasks to the Ant framework, like environment sets and an equivalent to the Unix "which" command. XHarness tests are executed by the Ant framework and the output produced by all tasks and the test results are captured. In that respect, XHarness works similar to the Ant junit task in that it runs testcases and tasks/processes associated with these tests and at the end produces an HTML summary of the tests, listing the result of each testcase as well as the output of the testcase's tasks and processes.

This is no longer active. All effort on this was merged into MVEL.

Maven Integration for Eclipse provides tight integration for Maven into the IDE. Dependency management for Eclipse build path based on Maven's pom.xml, automatic download for the required dependencies, quick search for Ibiblio repository, launching Maven from within Eclipse and much more.

Ashcroft is a drop-in SecurityManager implementation for Java which, when used in conjunction with a test-runner, prevents Unit tests from accessing files, network resources and doing other things which defy the definition of unit testing and slow down your test suite.

StaxMate is a light-weight framework that adds convenience to streaming XML-processing without significant additional overhead. It builds on top of Stax-compatible XML processors such as Woodstox , and offers two basic abstractions: cursors, which build on XMLStreamReaders, and output objects, which build on XMLStreamWriters.

GumTree is an open source and multi-platform graphical user interface for performing neutron scattering and X-ray experiments. It handles the complete experiment life cycle from instrument calibration, data acquisition, and real time data analysis to results publication. The aim of the GumTree Project is to create a highly Integrated Scientific Experiment Environment (ISEE), allowing interconnectivity and data sharing between different distributed components such as motors, detectors, user proposal database and data analysis server. GumTree is being adapted to several instrument control server systems such as TANGO, EPICS and SICS, providing an easy-to-use front-end for users and simple-to-extend model for software developers. The design of GumTree is aimed to be reusable and configurable for any scientific instrument. GumTree will be adapted to six neutron beam instruments for the OPAL reactor at ANSTO.

The Jikes Research Virtual Machine (RVM) is designed to execute Java(TM) programs and is typically used in research on fundamental virtual machine design issues.

This project provides a Castor JDO-specific implementation of the Spring ORM module, allowing users to use Spring ORM as their preferred choice of dealing with the persistence aspects of their applications whilst using Castor JDO as underlying persistence provider.

Agilifier provides a means for structuring, running and publishing for Agile/XP projects that use Story based acceptance tests using FIT.

Enunciate is a web service deployment framework (not another web service stack implementation). Enunciate provides a mechanism to build, package, and deploy your web service API. Enunciate compiles your source code and generates a web app that includes user-level documentation, a consolidated WSDL, SOAP endpoints, REST endpoints, JSON endpoints, client code, etc.

SXC stands for Simple XML Compiler. It allows you to compile optimized xml parsers and writers for various frontends.

Trails is a domain driven development framework for Java that aims to bring some of the excellent ideas of Ruby on Rails to the Java platform. By developing a POJO domain model with some annotations, it is possible to get a fully working Spring/Hibernate/Tapestry application without custom development. Trails does this without any source code generation and all screens are fully customizable as needed. As well, Trails provides other features such as validation, role based security and I18N.

ProphIt is a CPU profile visualizer written in Java and rendered using the GL4Java OpenGL bindings. ProphIt employs a novel 'tower diagram' that displays the proportional time usage of nested functions in an intuitive way, and facilitates navigating through the profile. ProphIt does not gather CPU profiling data; instead in includes file parsers for known CPU profile formats such as Java's hprof and the old -prof. ProphIt is working software with documentation. It was originally developed to be a commercial product but it is now being open sourced.

Fabric3 is a project implementing a federated service network based on the Service Component Architecture specification (http://www.osoa.org).

Waffle is a Java Web framework that allows for pojo-based actions. Dependency injection support is built in. Waffle does NOT have a proprietary templating language nor does it require any XML configuration files. Waffle apps are easy to write and test. We - the developers of Waffle (http://waffle.sf.net) and VRaptor (http://vraptor.org) - would like to join forces and first port Waffle to Codehaus (renaming it to use org.codehaus.waffle package) and gradually port features from VRaptor in order to create a larger and more consolidated community around a lean web application framework which honours the least-common-denominator principle. We greatly appreciate the Haus community and will abide by the Haus Manifesto. We hope that the new effort will further consolidate the already strong Haus branding as an incubator of high-quality commercially-friendly Java-based libraries. Mauro, Mike, Paul (for Waffle community) Guiherme, Paulo (for VRaptor community)

Jedi provides a library of routines inspired by more powerful languages such as Lisp, which support first order logic, filtering, iteration, type conversion of collections, etc. It makes extensive use of higher order functions and closures (also known as 'blocks' or 'lambdas'), but the key is that you do not have to write them yourself. The problem with closures in Java is that, while they really represent functions, they must be presented as objects. Since methods / functions are not first class objects in Java, any closure must be 'wrapped' in an object, which means creating a class, either named or anonymous. Jedi helps with this by providing JDK 1.5 annotations which will generate the necessary code. If annotations are used, JDK 1.5 is required at build time. However, the compiled code can be run under JDK 1.4 (using the javac -target jsr14 flag). No use is made of JDK 1.5 APIs in the generated code or the Jedi APIs, although generics are used to great effect. The generated code supports unit testing by providing several different ways to inject dependencies. You can therefore select the mechanism which supports your style of programming and testing. Jedi has been developed principally by three comitters with a few others making contributions here and there. It is about 1 year old and has been used on four investment banking projects and a project for a large ISP.

TestDox is an IntelliJ IDEA plugin that provides enhanced navigation and live documentation of JUnit tested code. TestDox has been developed by three comitters. It is about 4 years old and has over 10000 downloads to date according to http://plugins.intellij.net/plugin/?id=96 .

swiby stands for "Swing" and "Ruby", it defines a GUI builder DSL for user interfaces using the Java/Swing framework. It is inspired from the JavaFX scripting language. The project is in an experimental stage and should soon be in alpha release.

A convenience API for dealing with SQL from Java.

The purpose of the OpenIM project is to produce a fast, simple, and highly efficient instant messager server with high modularisation codebase. Check "OpenIM web site":http://open-im.org/ for more info. OpenIM 1.5 uses Plexus container. OpenIM is available on BSD License.

Marionette is focused on using AspectJ to splice into broken or clumsy parts of existing OSS systems, and exposing new hooks for controlling these systems. Currently, it consists of a tap into the Maven 2.0.x application that allows Before, Around, After(Any, Error, Failure) advice types to decorate a mojo execution. However, this principle can be applied much more broadly, to improve Maven and other projects even further. Once these taps are developed, each project will be rebuilt with Vampire Tap in place, and released as variant distributions. Currently, the project only has one committer: me. The project has just graduated the proof-of-concept phase, where I put together integration tests to prove that these advice types can be imposed on Maven's build process to control mojo execution. At present, the project has no public face at all, and no community.

A build system that uses Groovy as the scripting language and Ant tasks and Maven plugins as the mechanisms for creating actions. It can be thought of as Ant/Maven without the XML but very Groovy.

Sonar is an enterprise quality control tool, distributed under the terms of the GNU LGPL. Its basic purpose is to join existing continuous integration tools to place Java development projects under quality control.

JtestR is a tool that will make it easier to test Java code with state of the art Ruby tools. The main project is a collection of Ruby libraries bundled together with JRuby integration so that running tests is totally painless to set up. The project also includes a background server so that the startup cost of JRuby can be avoided. Examples of Ruby libraries included are RSpec, dust, Test/Unit, mocha and ActiveSupport. The vision of the project is to be the testing tool of choice for Java projects, offering nice Ant, Maven and buildr integration. It will also support integration testing with common Ruby libraries like Ruby/LDAP and ActiveRecord, while still providing access to Java libraries and helpers. The current implementation is still very young, and used only for testing itself. The aim is to release the first version within a few days from now, and gather reactions to steer the direction of the next release.

The next generation of JBoss Labs. Our aim is to create home for projects at jboss.org that is easy maintainable and user-friendly.

Jequel is an Java embedded DSL for SQL. Using its expressions one can easily create expression trees that can be rendered e.g. to SQL. Advantages: * code completion, syntax highlighting, error reporting in IDE * re-generate java schema-model during CI build, all non complying code will fail to compile * enhance the schema-model with lots of other information and have this at your fingertips (quick documentation lookup of your IDE) * generate browseable javadoc from the schema model files What exists by now: * Expression Language * small Generator Framework * Ant Tasks for Generation * Unit tests for all the above

IzPack is a Java-based cross-platform installer generator. This is the project development homepage. The public website is available from http://izpack.org/

GeoTools is an open source (LGPL) Java code library which provides standards compliant methods for the manipulation of geospatial data, for example to implement Geographic Information Systems (GIS). The GeoTools library implements Open Geospatial Consortium (OGC) specifications as they are developed, in close collaboration with the GeoAPI, GeoServer and uDig projects.

The main goal of Puzzle GIS is to create a free, multiplatform (Java based), production ready and competitive tool as a valid alternative to commercial software. Puzzle GIS is the evolution of AlterSIG project, initially created by Johann Sorel, based on NetBeans platform and GeoTools projects. - AlterSIG web page: http://altersig.developpez.com/index.php?page=p_altersig.php - NetBeans interview: http://www.netbeans.org/community/articles/interviews/johann-sorel-altersig.html Members of the Puzzle project are: - Johann Sorel, AlterSIG Project and also developer on the GeoTools project (http://docs.codehaus.org/display/GEOTOOLS/Home) - Antonio Santiago, from The Balloon Project (http://theballoonproject.blogspot.com) a virtual globe and probably another future open source project. - Theuns Heydenrych, software developer from Saab Systems South Africa. Currently there are other member pending to attach: - Steve Kruger and Martin Schmitz, from Atlas-Viewer project and, - Hans Schoebach, senior software architect from Galdos Systems Inc. software. If you wish some user recommandations, please ask us and we'll contact members of the GeoTools projects to push the request.

The project targets the Reference Implementation of JSR235 - Service Data Objects. The current source code while mature enough to be included in shipped BEA products is not yet finished as a JSR reference implementation. Links: - Current SDO specification - currently v2.1: http://osoa.org/display/Main/Service+Data+Objects+Specifications - JSR 235 http://www.jcp.org/en/jsr/detail?id=235

openXMA is a framework and a set of development tools (Eclipse plug-ins) for implementing Java thin, rich client applications. Basically, openXMA programs are web applications where client side Java code, based on SWT, will be downloaded and executed automatically. So look-and-feel like typical OS native rich clients is provided. Client code is cached locally, client and server halfs are communicating highly optimized via http. Please have a look to the project site http://openxma.codehaus.org/ to get more information.

qixweb was born by refactoring a few XP projects from the ground up. Its essential elements are: 1. an abstraction of node, each representing a page in a browser; each node is attached to some piece of the domain, but the domain is kept separated and clean ==> nodes may be connected directly to each other or via commands, which constitutes an abstraction of navigation of the entire webapp 2. an abstraction of command as action that will change the domain, producing a new node ==> ie: these commands may be used to wrap easily Prevayler commands 3. an abstraction of browser, url and link that keep nodes & commands well separated in turn from servlets and container aspects ==> it is therefore possible to test all the dynamic navigation logic server side without working with html, http or containers 4. an abstraction of response handler and renderer that enables browser to use template engines like Velocity on one side and that opens the world of multichannel applications on the other side

Gradle is a build system written in Groovy. It uses Groovy also as the language for its build scripts. It has powerful multi-project build support. It has a layer on top of Ivy that provides a build-by-convention integration for Ivy. It gives you always the choice between the flexibility of Ant and the convenience of a build-by-convention behavior.

Jackson is a high-performance streaming JSON parser/generator, nearing its "official" 1.0 release. Its API is similar to Stax API used for efficient xml processing on Java platform. Current home page is at http://www.cowtowncoder.com/hatchery/jackson/index.html.

Ever wondered how many lines of code or how many classes there are in the Sun JDK? Curious about the size of your own projects - or do you want to keep track of your work-progress. That's what JavaNCSS is for. JavaNCSS is a simple command line utility which measures two standard source code metrics for the Java programming language. The metrics are collected globally, for each class and/or for each function.

perf4j is a performance monitoring framework for Java. It includes a simple API for performance statistics gathering, with optional Annotation support. And classes for performance reporting (i.e. max, min, avg, stddev, TPM, etc.) with report options such as files and graphs. perf4j reporting may either be embedded, using incl