Spinneret is a structured storage engine that can be thought of as an extended tuple storage system. It takes the best aspects of relational, object, and hierarchical databases and throws away the dead weight associated with those technologies. The benefit of Spinneret is that its data model is incredibly flexible, allowing it to expose its underlying data in any number of ways. It operates similar to an object database, but without hard ties to an originating language, and can also behave like a relational database without the burden of complex joins.
JCons provides a library that bring color to your Java console. The Java console gives no methods to change the foreground or background color. With help of this library, one can make error messages red and success messages green, for example. Most Unix terminals can deal with ESC sequences, so they are used to make the Java console colorful.
FitNesse Maven Classpath Plugin is a Maven2 plugin that collects the dependencies of the entire project, including its sub-modules. After resolving the artifacts, it generates the classpath and inserts it into the Fitnesse test suites, thus solving the problem of maintaining the correct classpath in FitNesse.
Butterfly Web UI is a component based Java Web application framework. Like the rest of the Butterfly Components, Butterfly Web UI is extremely small and very flexible. Butterfly Web UI uses Butterfly Container internally, a state of the art dependency injection container. Using Butterfly Web UI, it is easy both to generate HTML for a Web browser or XML or JSON for a RIA frontend (Flex, JavaFX, Silverlight) or AJAX frontend. You also can easily create HTML layout templates that are reused throughout your Web application, so you don't have the layout hardcoded into every page. You can easily mix RIA and non-RIA Web application technology in the same Web application.
VRaptor3 is a fully-fledged Java Web framework focused on fast development and maintainable code. It intends to make RESTful application development easy. A resource corresponds to a business logic annotated with its path and HTTP method. It runs inside DI Containers (Spring or Pico out of the box) and, therefore, enables full integration with them. Also, using Hibernate is easier: its session is automatically injected by VRaptor, so you just have to use it. VRaptor3 is refactor-friendly, especially in its redirecting configuration. It is also nicely extensible.