Solia Online is one of the most active online communities with over 18 million posts. Solia Online allows you to create your own avatar, buy items, and discuss topics with your friends.
The Raspberry Pi is a cheap, credit-card sized computer. The official website uses phpBB for their discussion forums.
Discussion board for the massively popular xkcd web comic. Covering everything from Maths and Science to Logic Puzzles and Forum Games. Over 100k members and 2.4 Million posts.
Gentoo Linux is an open source operating system built on top of the Linux kernel and based on the Portage package management system.
Active community for UK based Audi TT owners. Almost 30k members and 2 million posts, complete with unique style & powered by phpBB.
Developed by Focus Home Interactive, Cities XL 2011 is a city simulation game. Their community forums are powered by phpBB.