Apache XML Graphics Commons is a library that consists of several reusable components used by Apache Batik and Apache FOP. Many of these components can easily be used separately outside the domains of SVG and XSL-FO. You will find components such as a PDF library, an RTF library, Graphics2D implementations that let you generate PDF and PostScript files, and much more.
ApacheDS is an LDAP and X.500 experimentation platform. Its backend subsystem and frontend are separable and independently embeddable. It provides a server side JNDI LDAP provider that directly interacts with the backend storage. It is powered by SEDA (Staged Event-Driven Architecture), which can handle large amounts of concurrency.
Apollo is an open-source developer test skeleton toolkit for Java Web Start/JNLP. It lets you turbo-charge Web Start apps without Web Start to speed up your compile/run/test/debug/goof-off cycle, avoiding the hassle of stuffing, signing, uploading, or downloading your jars every time you rearrange a comma in your source code.
AppFuse is an application for "kickstarting" Web application development. It allows you to execute a single ant task to create a skeleton application based on Struts, Spring, and Hibernate running on Tomcat and MySQL. It uses Ant, XDoclet, Spring, Hibernate (or iBATIS), JUnit, jMock, StrutsTestCase, Canoo's WebTest, Struts Menu, Display Tag Library, OSCache, JSTL, and Struts. (Spring MVC, WebWork, Tapestry and JSF are also options.)
AppInfo is a small library that provides an easy way to show always valid, automatically updated information about a version of running software in your Web or desktop Java application. It is especially useful with automatic builds from CI server deployed on QA. It currently supports displaying the name, version, build number, and build date of running software. This information is available as text from end application and can be customized to fit your needs. Source information can be passed via environment variables and works out-of-box with Hudson CI server.
Aranea is a hierarchical Model-View-Controller Web framework that provides a common, simple approach to building Web application components, reusing custom or general GUI logic, and extending the framework. The framework enforces programming using object oriented techniques with POJOs and provides a JSP tag library that facilitates the programming of Web GUIs without writing HTML. In addition to being a full-fledged Web framework in its own right, it provides a powerful and simple component system that allows the framework to be tailored by configuring the reusable modules and adding modules only for the missing features.
Architecture Rules is a Java library that allows a programmer to assert code's architecture via unit tests or ant tasks. This test is able to assert that specific packages do not depend on others and is able to check for and report on cyclic dependencies among your project's packages and classes. This project wraps a industry accepted JDepend to simplify the process of maintaining a solid software architecture.