So, while reading up on Groovy and Grails I wanted to play with it on my Ubuntu Hardy laptop. I already had the sun-java6-jre package installed so I could do standard Java stuff. However, in order to publish a Grails application, which is required in order to run it, you need the JDK. So I also installed sun-java6-jdk. It's possible I should have just removed the JRE and replaced it with the JDK, but the Ubuntu package manager didn't complain, so I didn't. I installed the Ubuntu groovy package, and downloaded the grails package and installed it with dpkg. Everything looks good, I can run 'grails help' from the command line without errors. So I create my grails app.