Tapestry Palette is a plugin for Eclipse that builds upon the Spindle plugin. The palette provides a tree view of Tapestry component libraries, a component inspector to discover parameters available with links to HTML documentation, drag and drop addition of Tapestry component references to templates, and a Property Sheet for editing of component bindings. The plugin can be installed from within Eclipse via an update site.
Necessitas is an Eclipse plug-in that adds a class-path container to manage a projects jars using the ivy dependency manager. It gives you all of the advantages of ivy without leaving Eclipse. It will download the jars your project depends on and add them to your projects classpath. You can optionally have it automatically update your classpath whenever a change is made to the ivy module.
Drools is a Rete-based rules engine written in Java, but able to run on Java and .Net. it is designed to allow pluggeable language implementations. Currently, rules can be written in Java, Python, and Groovy. It also enables domain-specific languages (DSLs) via XML using a schema defined for your problem domain. DSLs consist of XML elements and attributes that represent the problem domain. An XML authoring tool provides a semi-rapid development environment with a drag and drop type interface based on the provided schema.