Java was developed by Sun MicroSystems. Sun distributes (freely) the Java Development Kit (JDK). (At the time of writing the JDK was at version 1.1.5 for Windows platforms.) The JDK has the following:
java - Java Interpreter
javac - Platform independent Java compiler.
javadoc - Generates documentation from source code
You can down load these tools from the above link.
Consider the following Links:
b) or back to Java's Main Uses
n) or next to Your First Java program
or
x) or out to Java History and Overview