The 10th Anniversary depends on what you consider our go-live date.
This teaser went live in June 2002:
http://web.archive.org/web/20020624033636/http://www.originaltrilogy.com/
The original petition and forum went live on March 10, 2003:
http://web.archive.org/web/20030329102201/http://www.originaltrilogy.com/
My forum join date is a couple weeks prior to that because I installed and tested the old software before the launch.
I'd say the 10th anniversary is tomorrow.