You must have adequate disk space to install JDK and JBoss Application Server while also allowing enough space for your applications. Before installing JBoss Application Server you must have a working installation of Java. Since JBoss is 100% pure Java you can have it working on any Operating System / Platform that supports Java. However there are a few Operating System-specific issues that you must be aware of. Refer to http://wiki.jboss.org/wiki/Wiki.jsp?page=JBossOperatingSystemSpecificIssues for more information.