I haven't played with a new tool in a long time that I have liked this much out of the gate.
Megan Sumrell - Misys Healthcare Systems

We absolutely love this plugin! We can not wait to introduce GreenHopper to our production line JIRA
Eric Salonen - AMBIENTIA LTD. - DIGITAL BUSINESS AWARENESS

Your product is very good. It is very easy to use and has already saved us hours of planning time. Congratulations.
Michael Green - BarNetwork P/L

This plugin for JIRA is a jewel.
Brendan Lawlor - DIS

Well, that GreenHopper thing is insane. It is not only awesome for mannaging projects but also for managing our bugs. In all fairness I don't see JIRA without GreenHopper.
Olivier taken from the JIRA-user Forum

I. Web Blogs & Forums

Agile - tools & process, simply a reference! ONTIC OREN
Living the ultimate online agile workflow

An interesting blog from Alexander Brill on Digital vs Post-it
Agile project management tools - Digital vs Post-it

A blog from Oren Teich on JIRA-Confluence-GreenHopper ONTIC OREN
Using Jira, Confluence & Greenhopper for Agile

A blog of a GreenHopper user TomTom, and its experience with the plugin
Tracking progress the easy way

A blog from Megan Sumrell on Agile~Megan Sumrell's Weblog:
GreenHopper - great tool!

A blog from Brendan Lawlor on DeCare Systems Ireland Blog
Managing projects with JIRA and GreenHopper

A blog from Andrej Koelewijn on it-eye:
Project management with bug databases

An interesting thread from the JIRA-user Forum:
Evidence Based Scheduling

A blog from Dave Garrett on www.gantthead.com
Project Management 2.0

A blog from leuc on Leuc's Blog in French!
GreenHopper : la planification XP

Another blog in French talking about agile product on Coder Peon
La panoplie des logiciels pour développer des projets agiles

A bloh from Gerd on Gerd's dev 2.0 Blog
Agile JIRA

A tiny blog from PGTaboada on adminSight
Agile Project Management Tool for JIRA

Atlassian Developer blog
GreenHopper 1.6 and 1.7

Atlassian Developer blog
New JIRA Plugin: GreenHopper, for Agile Teams

Atlassian News blog
GreenHopper - Project Management Tool for JIRA

II. Announcements

Announcement on TheServerSide.com
Pyxis Technologies releases GreenHopper 1.6

Announcement on TheServerSide.com
Greenhopper released for project management in JIRA

Announcement on TheServerSide.net
JIRA for project management

Announcement on application-servers
application-servers