OpenCart is popular, powerful, and easy to use shopping cart software. Their healthy community forums are powered by phpBB.
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.
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.
Inspired by Max Berry's book, Jennifer Government, NationStates is one of the most popular online simulation games. The forum boasts over 5 million posts and 200,000 users.
Waze is the world's largest community-based traffic and navigation app. Join other drivers in your area who share real-time traffic and road info, saving everyone time and gas money on their daily commute.