linux VM on a windows server
At the time, I was doing linux kernel development (drivers, specialized firmware, etc.). As the linux kernel has case-sensitive files in it, some of which have name clashes with other files [if case-sensitivity is NOT in your source code repository], we had to install the source code repository software onto a Linux machine. Well, we were using a few VMs by then, being (often) cheaper than actual hardware, but for some odd reason we were told to CREATE THE LINUX VM for the repository on a WINDOWS SERVER COMPUTER, because, *ahem*, it was MORE RELIABLE that way. [it was previously hosted on the SAME windows box, which wasn't hosting ANY OTHER VMs at the moment, or anything important at all, as I recall]. Turning that windows server machine OFF and then replacing with a Linux server would PROBABLY have cost less, too. But NOooo... we had to put Linux in a VM to host the source repository, then host it on a WINDOWS SERVER computer.
Yeah. "More reliable." Well, my supervisor was a fan of C-pound, ".Net" and Windows Vista, too...