Java runtime based on OpenJDK, [[http://icedtea.classpath.org/|Icedtea]] is a temporary supplement to [[http://openjdk.java.net/|OpenJDK]]. It is meant as a free-software supplement to the binary plugs provided by Sun Microsystems to build OpenJDK. Once these "plugs" are officially "freed", the work will be merged upstream as required.

For more information, have a look at the [[http://icedtea.classpath.org/wiki/FrequentlyAskedQuestions|OpenJDK FAQs]].