I got sucked in to a bit of back and forth on our local Linux/Unix list a couple days ago and wrote:
Ten years ago I was consulting for a multi-national education non-profit, and I discussed with the systems manager the notion of using open source…in particular I was talking about replacing their Windows 2000/NT servers, with Linux. This would have been a logistical wrench, not least because they had several client/server applications that used SQL-Server as the back end. His point was that as an educational institution, they got such good discounts on any proprietary software that the amount spent on the software was a miniscule percentage of their IT budget. So, there was no economic benefit, and certainly no performance benefit that justified such a change.
Later that year I was doing an inventory of their machines at one of the european sites and couldn’t find the terminal server box. Turns out this was a Linux box running VMC or something and it had been bricked up in a wall during a recent renovation, and been merrily running, unseen, for several months.
So, the moral for me was, use what works. At the time I actually got them to go from running four O/S’s in the organization to two, Windows, and the aforementioned Linux. We dumped Macs in one site, and Novell in another, and my advice to subsequent clients was to run one and only one OS in the organization.
I’m happy to say that they didn’t all run Windows.