Hello,
I've downloaded the JBoss installer [1] and I tried to run it with my JRE:
florian@horus ~/Desktop $ java jboss-4.0.3SP1-installer.jar
Exception in thread "main" java.lang.NoClassDefFoundError: jboss-4/0/3SP1-installer/jar
You are missing the -jar argument:
florian@horus ~/Desktop $ java -jar jboss-4.0.3SP1-installer.jar