I've been with my current employer since easter 2002. The factory's real-time system is DEC based. A DS-20, an Alphaserver, even a couple of old VAX servers still in use. There were also several Windows servers when I started: Domain controller/File server, Proxy, Exchange and Accounting. Users in the office have win2k desktops. In the factory we had, and still have, vt-420 terminals. There was no Linux.
Microsoft Proxy server 2.0 is nasty. Requires constant attention and regular reboots. My boss was therefore open to the idea of replacing it. I had a Linux proxy/firewall installed faster than you could say "Hey let's install Linux here". Originally I used Mandrake 9, because I happened to have MDK disks. Later we standardized on Debian.
In early 2003 three of the five disks in our Exchange server's RAID array failed simultaneously. The array was therefore trashed. Furthermore due to a configuration error recent backups were not available.
This was an excellent opportunity for me. So long Exchange. Bye bye per-seat licensing. Hello Postfix + Spamassassin + Anomy Sanitizer, and reliable email serving.
Meanwhile at home I was up to version 9.0 of Mandrake, and still mostly using Win2k. But that's a story for part three...