[qwery]

It's an interesting comparison. I agree that five years is well within the expected period of viability of an operating system. Some points to consider:

- any given release of a Linux distro will probably work on hardware released five years earlier -- one factor that reduces the cost of upgrading the OS (there are many more obvious factors)

- Microsoft is highly motivated to get customers to upgrade to the new Windows at the time. The legacy support is well-known as a "bone" (or: "a factor that reduces the cost of upgrading the OS")

- binary backwards/forwards compatibility is less of an issue in an environment that doesn't treat source code as a secret

- why run old versions of software? In other words: xterm is older than Windows and also as new as Windows

Also, I've always found it amusing that I have much less trouble running old windows software on a Linux (wine) than on new versions of windows.