Groovy

Another language to look at which contains features of Python, Smalltalk, and Ruby.

From the site:
Groovy is an agile dynamic language for the Java 2 Platform that has many of the features that people like so much in languages like Python, Ruby and Smalltalk, making them available to Java developers using a Java-like syntax.

Groovy is designed to help you get things done on the Java 2 Platform in a quick, concise and fun way — Groovy brings the power of a scripting language directly into the Java 2 Platform. For example:

• Shell scripting using Groovy allows the full power of the Java Platform to be brought to bear to the task at hand.
• Groovy can be used (and indeed is already being used) as a replacement for Java for small and medium sized applications to execute on the Java 2 Platform.
• Groovy can be used as an embedded language for dynamic business rules or extension points utilizing the agility of Groovy and saving the cost of redeploying applications for each change of rule (especially when the rules are stored in a database).
• Groovy makes writing test cases for unit tests very easy.

As well as being a powerful language for scripting Java objects, Groovy can be used as an alternative compiler to javac to generate standard Java bytecode to be used by any Java project.