KDE is mainly known for producing the KDE Desktop Environment (used in Kubuntu) for Linux.
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.
Gentoo Linux is an open source operating system built on top of the Linux kernel and based on the Portage package management system.
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.
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.
OpenCart is popular, powerful, and easy to use shopping cart software. Their healthy community forums are powered by phpBB.