Using Helma NG with OpenJDK
OpenJDK, which is the default Java implementation on various Linux distributions, has a long-standing bug that makes it difficult to run other versions of Mozilla Rhino than the one shipped with the distribution.
In this case, you may consider switching to a different Java implementation. For example, to install Sun's version of Java and make it the default on Ubunutu 9.04 (Jaunty Jackalope), use the following commands:
sudo aptitude install sun-java6-jdk sudo update-java-alternatives -s java-6-sun
You should now have the official Sun JDK installed as default Java implementation.