The Way the Update Center Works - Grails 1.0.4 for GlassFish
By pelegri on Nov 17, 2008
Download GlassFish v3 Prelude, and check the update center for the new packages (you can do it directly from the admin console); then select the "grails" component and install it. Wait a bit (it is 49MB!) and there you go. Also check out Vivek's presentation on Scripting in GFv3 Prelude and Alexis' Grails Intro Screencast.