How to check if you have Java installed
Java Runtime Environment (JRE) version 1.4.2 or greater must be installed for Lucid3 to run successfully. To check if you have Java installed on your system, type:
in a Command prompt (Windows) or Terminal console (Mac, Unix).
If you receive an “Unknown Command” error message or your Java build number is less than 1.4.2 then you need to install the latest (free) edition of JRE, which can be found at http://www.java.com
For help installing the JRE please see: http://www.java.com/en/download/help/index.jsp
For FAQs on the JRE please see: http://www.java.com/en/download/faq/index.jsp