Munich (as city in Germany) started a transition from Microsoft Windows NT 4 and Office 95 (the migration started in 2004, and is a slow, ongoing process).
Munich is slowly rolling out their own distribution of Linux, which means that they control what versions of what software they have.
They can easily update all machines with little work by the IT department (most Linux distributions come with a built-in update checker, which can often be configured for a set amount of time between check-ins).
They have lost (some) compatibility with some versions of Microsoft Word. But migrating to Office 2007 would have the same problems as migrating to OpenOffice/Libreoffice.
This post is about the recent study funded by Microsoft and conducted by HP.
In that study, it was found that the open-source migration was "significantly" more expensive than staying with Microsoft products.
Lets study a hypothetical situation. These numbers are not ACTUAL numbers. They are numbers that come from some of my experiences, but they are NOT ACTUAL NUMBERS.
A company (Alice's and Bob's Random Company) has 12,000 desktops, all of them made before 2004. They didn't shell out a bunch of money for those desktops, which means that the desktops most likely have 512 MB (or less) of RAM, a 1.6 GHz CPU and (maybe) two cores. They also have 40 GB hard drives, and integrated graphics.
Those machines cannot run Windows Vista or later. The RAM requirements are too high for those machines. If they do test a machine with more RAM and Windows, they find that the integrated graphics is not powerful enough to run Windows Vista or later at a comfortable speed. They can upgrade the components, but how much RAM does the motherboard and CPU allow? At this point, they might as well get new computers at ~$350 per computer.
That is 4.2 million dollars right there. For a bare-bones machine.
They will reinstall Windows, if it was installed in the first place.
If it was not installed, then add $50 per license for Microsoft Windows (OEM is $99). That is an additional $600,000, if they have to get licenses for Microsoft Windows. This cost may not exist, so this won't be factored into the final numbers.
They will have to get a new version of Microsoft Office (~$250 for cheapest Business/Government acceptable option). Lets say that they manage to negotiate a deal with Microsoft for Office and get it for $125 per license. That is $1.5 million as compared to the $3 million they would otherwise pay.
So far, the total costs for upgrading their infrastructure to a more recent (and thus supported) version of Microsoft Windows is around $5.7 million on the cheap end.
Training for the Ribbon interface: 1-2 hours per employee, 12,000 employees, and on average $30 is spent on per hour on training. Cost: $360,000 to $720,000.
So lets go on to Linux.
They can keep their current computers (if they use LXDE or XFCE), which means that they don't have to spend $4.2 million on new machines. They just use the machine until it dies, not until it is made obsolete by new versions of an operating system. They still end up paying $4.2 million, but its over a longer period.
They switch to OpenOffice/Libreoffice. They do have some compatibility problems, but Microsoft Office had similar problems. They spend $1.5 million in Office licenses (minimum, if they purchase it off the shelf then its $3 million).
They have legacy software that won't run under Linux. They use WINE for programs that work, file bugs on the rest, and keep a few machines with NT 4 around, or Windows 7 if the programs work (which they may not).
Training for the new OS interfaces: 1-2 hours per employee, 12,000 employees, and on average $30 is spent on per hour on training. Cost: $360,000 to $720,000.This is assuming that the company doesn't spend time getting a Desktop Environment that has the same workflow as Windows, in which case the training costs go down significantly.
1-2 hours per machine at $20 per hour. That is $240,000 to $480,000.
Total Costs (minimum):
$4.92 million (Linux)
$6.06 million (Windows)