As promised, Gruple has moved from Googlecode to Codehaus. You find it’s new home here: http://gruple.codehaus.org.
All the documentation has been ported. There are new mailing lists. The source is now in a Git repository. And the 1.1.1 distribution is available from the distro site. Everything is (or should be) linked to from the main page.
Thanks to everyone who commented or helped.