Our virtual community, which has been in operation since 1996, now runs on a Debian GNU/Linux server (replacing what was originally a Sun Enterprise server, then a slew of Windows NT Server boxes). Debian has been my favorite distro for some time now, and its ease of performing system updates combined with its ease of customization and its overall stability made it a natural choice for our community-purchased server. The server runs our Web community software, the Venice Web Communities System http://venice.sourceforge.net, on top of Apache, Tomcat, and MySQL.
Nothing short of catastrophic disk failure has been able to take our server offline since it was deployed. We're proud to display Debian's logo on our Acknowledgements page http://www.electricminds.org/venice/frame/eminds/eminds-credits.html.