Greg has been a participant in the Fedora community since 2004. It's been a grand old time.
Greg is the founder of Digital Commoners, a consulting firm that specializes in the practice of open source community development. Previously, Greg was the Chief Technical Officer for the Institute for the Study of Knowledge Management in Education, and before that he was a Senior Community Architect at Red Hat.
Here's a great list of stuff that Greg has learned over the years.