Conquer Club is an online multiplayer world domination game. The discussion forum is host to over 500,000 members and 2.8 million posts.
Developed by Focus Home Interactive, Cities XL 2011 is a city simulation game. Their community forums are powered by phpBB.
Joomla is one of the leading open-source Content Management Systems. With a userbase of over 400,000, they use phpBB as a reliable platform for support.
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.
KDE is mainly known for producing the KDE Desktop Environment (used in Kubuntu) for Linux.
Adblock Plus is one of the most popular Firefox Add-ons in the world, with over 10 Million daily users and over 100k downloads a day. They use phpBB to offer support to their users.