"Citius, Altius, Fortius!" This motto should definately be addopted by phpBB, because its true!
phpBB uses php and MySql - A well proven combination, possibly the fastest for making a good forum possible.
phpBB is always striving to make sure it includes the features that the community feels would add to it, which is one of the greatest things about the phpBB team - they interact with their users and actually listen to feedback.
phpBB is robust - VERY robust. Its as (hacker/spammer/lamer)-proof as anything out there, and you wont find a more bug-free board in miles.
Well done to the phpBB Group, you've successfully outdone anyone in the past - you've created the perfect forum.