Download JDK 5 bzw. 6
(Java Compiler + Interpreter JRE)


Java 5
Download  "JDK 5 Update x"
http://java.sun.com/javase/downloads/index_jdk5.jsp
Information
http://java.sun.com/j2se/1.5.0/system-configurations.html


Java 6
Download  "JDK 6 Update x"
http://java.sun.com/javase/downloads/index.jsp
Information
http://java.sun.com/javase/6/webnotes/install/system-configurations.html