Recently I've had some discussion with colleagues about Mac OS X, Windows, and Linux in comparison to each other. Generally, I've found that most people agree that Mac OS X is more stable than Windows, and those that are familiar with Linux feel that it too is more stable than Windows. But after that being said, they come back with an apology for Microsoft stating that they (Microsoft) have to get Windows to run on fragmented hardware, whereas Apple standardizes the hardware and can therefore provide a more stable operating system for it, because there aren't nearly as many variations in hardware configurations.
I agree that Apple definitely has an advantage because of the consistent and standardized hardware platform to run on. Windows does have an enormous amount of Intel hardware that it must run on, so the argument I commonly hear is that Microsoft can't possibly run consistently for each separate hardware scenario, and that this causes instability issues.
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