Tamay Dogan Network GmbH is Non-Profit Enterprise supported by the German Government, UNDP and UNESCO. We are working in Germany, Iran, Turkey, Morocco and Tunesia. Our entire infrastucture is Debian-based since 1999. We are using Apache2 with PHP5, ProFTPd, PostgreSQL, Courier, Fvwm, IceApe/IceWeasel, OpenOffice and a bunch of developer tools. Also I am packing Debian packages for more than 6 years now. We run the following (dedicated) physical servers: 12 routers/firewalls, 23 PostgreSQL (smallest 2 GByte and biggest 1.8 TByte), 18 webservers, 7 Courier, 25 NFSv4, 1200 embedded telemetry systems (for solar power plants) and of course about 50 workstations in offices, 160 Workstations in Cybercafes.
I started in March 1999 using Debian 2.1r5 Slink by switching away from Windows NT 4.0 Server in a day-to-day operation and it just worked. Because of the enormeous stability, we have stayed for 10 years with Debian and continue to do so.