The VideoLAN project produces the extremely popular VLC media player software. Their forums provide support for users of the software as well as the development community.
Support for Synology NAS devices and ideas for future versions of the DiskStation software.
VirtualBox, developed by Oracle, is cross-platform x86 virtualisation software. It has become one of the most widely used virtualisation solutions in the world.
Discussion board for the massively popular xkcd web comic. Covering everything from Maths and Science to Logic Puzzles and Forum Games. Over 100k members and 2.4 Million posts.
GameServers is a premier Game Hosting company, having collaborations with big names such as Infinity Ward, Treyarch and Epic Studios.
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.