Gentoo Linux is an open source operating system built on top of the Linux kernel and based on the Portage package management system.
Conquer Club is an online multiplayer world domination game. The discussion forum is host to over 500,000 members and 2.8 million posts.
Active community for UK based Audi TT owners. Almost 30k members and 2 million posts, complete with unique style & powered by phpBB.
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.
The Raspberry Pi is a cheap, credit-card sized computer. The official website uses phpBB for their discussion forums.
As the official board for the world-famous band Queen, this community hosts a wide variety of discussions by Queen fans from around the globe.