Groovy - An agile dynamic language for the Java Platform
(JavaDoc for Java classes)

Groovy...
  • is an agile and dynamic language for the Java Virtual Machine
  • builds upon the strengths of Java but has additional power features inspired by languages like Python, Ruby and Smalltalk
  • makes modern programming features available to Java developers with almost-zero learning curve
  • supports Domain-Specific Languages and other compact syntax so your code becomes easy to read and maintain
  • makes writing shell and build scripts easy with its powerful processing primitives, OO abilities and an Ant DSL
  • increases developer productivity by reducing scaffolding code when developing web, GUI, database or console applications
  • simplifies testing by supporting unit testing and mocking out-of-the-box
  • seamlessly integrates with all existing Java objects and libraries
  • compiles straight to Java bytecode so you can use it anywhere you can use Java
Packages 
Package Description
groovy.util  
groovy.util.slurpersupport
Helper classes for XmlSlurper.
groovy.xml
Groovy markup builder classes for working with SAX and W3C DOM and Groovy markup.
groovy.xml.dom
Groovy XML Dom processing classes.
groovy.xml.slurpersupport
Helper classes for XmlSlurper.
groovy.xml.streamingmarkupsupport
XmlBuilder related classes to support streaming XML.
org.apache.groovy.xml.extensions  
org.apache.groovy.xml.tools  
org.codehaus.groovy.runtime  
org.codehaus.groovy.tools.xml