According to Brian Moon's blog today, the popular PHP forum package Phorum has hit the 10 year mark in its development:

So, I am at the MySQL Conference this week with my Phorum co-developers. We got to talking last night about how old Phorum is. We knew it was about 10 years. We pulled up some old archived zip file of version 1.5 and found in the this in the comment block. "* Created 04/16/1998" Whoa! That means that yesterday was the 10th birthday of the Phorum project.

The current version of Phorum is 5.2 stable and can be downloaded directly from their site.