Info-Mac
Info-Mac is a community dating back to 1984 as a mailing list and was the first online community for Apple's Macintosh computer. All of their content was converted to phpBB in 2007.
Solia Online
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.
Gentoo
Gentoo Linux is an open source operating system built on top of the Linux kernel and based on the Portage package management system.
Raspberry Pi
The Raspberry Pi is a cheap, credit-card sized computer. The official website uses phpBB for their discussion forums.
Ubuntu Italy
It is the Italian Community for Ubuntu, a popular open source community operating system based upon the the Debian Linux Distribution.
CitiesXL 2011
Developed by Focus Home Interactive, Cities XL 2011 is a city simulation game. Their community forums are powered by phpBB.