NationStates
Inspired by Max Berry's book, Jennifer Government, NationStates is one of the most popular online simulation games. The forum boasts over 5 million posts and 200,000 users.
Bokt.nl
Independent site for Dutch horse lovers. With over 150,000 members and 70 million posts, Bokt.nl is widely acclaimed as one of the largest boards powered by phpBB.
Gentoo
Gentoo Linux is an open source operating system built on top of the Linux kernel and based on the Portage package management system.
OpenOffice.org
OpenOffice.org offers a free and fully-featured office suite which meets the needs of the common consumer all the way up to large enterprises.
Sky Italy
Italy's home to the multi-national media giant, Sky. Sky's range of enterprises include digital television, broadband, phone lines, news broadcasting and sport broadcasting.
Meristation
Meristation Magazine is a Spanish-language website featuring articles on gaming. Their discussion forums hold over 34 million posts and are powered by phpBB.