Learn how you can install Sun Java JDK (Java Developement Kit) / JRE ( Java Runtime Environment ) in Open source operating system like Ubuntu , Fedora and Open Suse. JDK - Is used to develope the java application with the help of Java Libraries. JRE - Is used to run the java application Java is Independent platform and also more secure. To Install Sun Java (JDK/JRE) in Ubuntu sudo apt-get install sun-java6-jre sun-java6-plugin sudo update-alternatives –config java To Install Sun Java (JDK/JRE) in Fedora yum install sun-java6-jre sun-java6-plugin To Install Sun Java (JDK/JRE) in Open Suse yast install sun-java6-jre sun-java6-plugin