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.
The Raspberry Pi is a cheap, credit-card sized computer. The official website uses phpBB for their discussion forums.
VirtualBox, developed by Oracle, is cross-platform x86 virtualisation software. It has become one of the most widely used virtualisation solutions in the world.
Active community for UK based Audi TT owners. Almost 30k members and 2 million posts, complete with unique style & powered by phpBB.
12 Chat Forums is one of the largest and most active social and chat communities in the Arabic language. Their community boasts nearly 2 million posts and 80,000 users.
KDE is mainly known for producing the KDE Desktop Environment (used in Kubuntu) for Linux.