On the server side, we use Linux whenever possible. The first steps with UNIX we did 1984.
Since then we work with AIX, Solaris and Linux. Linux we know since kernel version 0.92.
Today our preferred distributions are
The primary choice of a distrubtion depends on the selected hardware and the needed functionality.
The use of Linux Desktop was replaced with Apple Mac.
We use Linux to build logserver, webserver, DNS-server, database-server, voip-server, mail-server, anti spam gateways, cheap firewalls … The list is almost endless.
Almost everything is possible. If you got a question about Linux, just call.