It is the Italian Community for Ubuntu, a popular open source community operating system based upon the the Debian Linux Distribution.
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.
Developed by Focus Home Interactive, Cities XL 2011 is a city simulation game. Their community forums are powered by phpBB.
Zend Technologies is one of the largest and most popular companies producing a wide variety of tools and frameworks for PHP. Their community forums rely on phpBB.
OpenCart is popular, powerful, and easy to use shopping cart software. Their healthy community forums are powered by phpBB.