I'm using Jira and have been told by the sysadmin that GreenHopper has been installed.
However, I see no evidence that GreenHopper has been installed.
Is there a simple way to determine whether or not GreenHopper has been installed?
Once greenhopper is installed, it needs to be enabled for the project. In the greenhopper administration section you can choose to enable it for all projects or only selected ones.
I believe the default setting has it only for selected projects, with none selected.
Edit: you can find that setting in the administration section under Greenhopper -> Enabled Projects.