Were it not for Windows' longstanding installed base and overwhelming market dominance, it seems unlikely that anyone would argue seriously for the merit of the operating system, plagued as it is by high prices, security problems and vendor lock-in.
Apple OS X, however, is another matter. Though certainly a minority, Mac fans are passionate and vocal enough to make it clear that Apple must be doing something right, whether that "something" has anything to do with the technology or not.
As an outspoken fan of Linux, I'll make no bones about where my preference lies, and that I think the success of the Mac is mostly a matter of marketing. Whatever your own personal beliefs, though, there's no denying that there are certain things Linux clearly does better than Mac OS X. If you're trying to decide on a platform for your business, these factors are worth keeping in mind.
The Mac might enjoy a smaller installed base than Windows does, meaning there's less of the monoculture effect and less of a lure for malicious hackers, but Linux blows them both away when it comes to security.
First is the question of permissions: Linux users are not automatically given administrator privileges on their computers, meaning that viruses and malware don't automatically have access to everything in the proverbial "castle." So, when a computer is compromised, the most the malware can typically do is trash the user's local files and programs.
With Apple, as with Windows, social engineering is painfully easy. Just convince the user to click on something, and away you go, with the castle keys in hand.
Apple is also notorious for trying to "protect" users in its "walled garden," keeping all the inner workings of the computer secret and out of view. It's even more extreme in this respect, in fact, than Windows is. The only ones who can see and watch for vulnerabilities in the code, then, are Apple engineers, who understandably have their own priorities and timetables.
With Linux, on the other hand, there is a world of users examining the code every day. No wonder, then, that Linux vulnerabilities can be found and fixed more quickly. Recent data backs this up. Research firm Secunia recently found that Apple now "outshines" even Windows in the number of security vulnerabilities associated with its products.