GameServers is a premier Game Hosting company, having collaborations with big names such as Infinity Ward, Treyarch and Epic Studios.
The VideoLAN project produces the extremely popular VLC media player software. Their forums provide support for users of the software as well as the development community.
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.
KDE is mainly known for producing the KDE Desktop Environment (used in Kubuntu) for Linux.
Discussion forum for the massively popular American animated sitcom. Powered by phpBB.