Why use GNU/Linux?
Why should I use GNU/Linux rather than Windows, OS X or something else?
Short Answer: Security, Privacy, Speed, Customization, Cost & Freedom
Strong Immune System
If you buy an ordinary PC, it probably came with Microsoft Windows. Most people figure that's good enough for them, or even “upgrade” to the newest version of Windows to keep up to date. But Windows has a lot of problems. First off, it's very prone to computer viruses and attacks. It's true that a very careful and knowledgeable Windows user can usually keep his computer virus-free, but this is not the usual scenario. With GNU/Linux, even a less experienced user will run a much more secure and virus-free system. In fact, viruses are virtually unheard of on GNU/Linux.
Frankly, OS X is very solid on this front as well, in part because both OS X and GNU/Linux come from the same common, secure UNIX heritage.
GNU/Linux needs no Validation
But say you want to add or change some hardware to your Windows PC. You might find yourself locked out of some of the features you need in Windows and Windows will complain that it is “not genuine,” even though you bought it with your PC fair and square. To solve this, you will have to contact Microsoft, verify that that is still the same PC and ask Microsoft for permission to “validate” your Windows copy. Doesn't sound very American, does it? If a PC depends on its OS and your OS is controlled by Microsoft, who do you think is ultimately in charge of your PC? Not you, that's for sure!
With GNU/Linux, you never have to ask anyone permission to do anything on your PC. GNU/Linux will always be “genuine” no matter what PC you run it on, or what you do to it. You will never have to “verify” or “validate” your hardware to anybody. It's truly yours to do with as you please and totally under your control.
Apple is much more user-friendly when it comes to OS X. You never have to “validate” your Mac to Apple. But you can't install OS X on a non-Apple PC without some serious hacking, so you have to accept Apple's limited hardware selection and pay the Apple tax to use OS X.
Doesn't get Home Sick
Of course, Microsoft's nasty tendencies don't end there. Windows tends to “call home” every now and then, potentially violating your privacy. After all, why should your OS be “calling home” if you don't want it to? Normally, this is not an issue on GNU/Linux, and where there are potential privacy issues, they can be turned off with a few simple commands. Again, GNU/Linux is under your control.
OS X also calls home, even if you tell it not to (I guess Apple knows best!) You can stop this Apple “feature” only by purchasing special software.
Another nasty habit of Windows, as anyone who's upgraded an older PC knows, is slowing you down. Newer versions of Windows tend to use up significantly more resources on a PC, thus slowing it down. This, in itself, might be a great reason to install GNU/Linux. GNU/Linux tends to be a lot more resource-conscience, so it tends to run a lot faster on older PCs. That super-slow PC you can't bare to use anymore? It's now youthful and useful again with a fresh install of GNU/Linux on it!
OS X fares far better on newer Macs, but Apple gets to arbitrarily choose which Macs can run the latest version and features and which can't.
Embraces Your Style
Apple believes that “customizing” means changing your desktop wallpaper. Microsoft keeps trying to “innovate” with squares and strange shades of color, but keeps on winding up in the same place. In GNU/Linux, you are not subject to corporate whims and can customize every aspect of how your system looks and behaves. Changing how your windows and menus look is only the beginning.
But for many, the best part is- that it's absolutely FREE! People spend hundreds of dollars “upgrading” to the latest Windows version. But for a REAL upgrade, you can put your purse or pocketbook away! GNU/Linux won't cost you a cent- and that's the full-fledged authentic real-deal. We're not talking GNU/Linux “Lite” here. All those savings really start to add up after a few years. You can buy that new TV or gadget you've always wanted. Or better yet- you can give to the poor or donate the amount YOU want to the authors of the GNU/Linux programs YOU want to give to. You can be certain that they will really appreciate it.
With Apple, most OS X upgrades are free or inexpensive, but you have to pay for Apple's admittedly quality, but pricey and limited-selection hardware. For example, although Apple's entry-level Mac costs $500, it can't be upgraded in many ways as your needs grow. And of course, Macs get much more expensive from there.
But perhaps the most important point to make here is that by supporting GNU/Linux, you are supporting your own freedom and those of others. How so? Well, by supporting free and open-source software, you support software that doesn't “lock you in” into only one vendor's software or products, and you are using software that you and others can modify and use as you see fit, without asking anyone for permission.
Even if you aren't planning to become a programmer, you can be sure that other people will respond to an important community issue if the need arises. Often software will “fork” into two or more versions to fit the differing needs of the community- an option not often available outside of free and open-source software like GNU/Linux. And old software doesn't have to die because the author or company lost interest in it- someone else can always pick up and keep it alive, without worrying about getting into any legal trouble.
But perhaps even more striking is the different in fine print. When you update or install Windows or OS X, take a look at the fine print. Go ahead- read some of it. What do you find? It's full of restrictions and all kinds of conditions you need to legally agree to just to use your computer! Now, when you install GNU/Linux, take a look at the fine print. What you will find is the polar opposite. You're free to do just about whatever you like with GNU/Linux, so you can click “Agree” with confidence.
What's the catch?
I'm a GNU/Linux user and fan, not a slick salesman. I won't deny that there is indeed a “catch” to GNU/Linux. Namely, GNU/Linux isn't quite as “polished” as OS X or even Windows, in some aspects. Basically, what this means is that it won't often look as pretty or work as seamlessly out-of-the-box. This is because of the way GNU/Linux is developed- as a community project, with many voices and wills, not as a corporate project with one agenda and director. It also means you will probably have to use the TERMINAL command line occasionally. But don't worry, it's more fun than scary!
Also, though GNU/Linux runs on just about everything, it some times can't take full advantage of special hardware features. This is because many hardware developers don't bother writing the appropriate software (drivers) to do so, or even documenting the hardware so that others in the GNU/Linux community can. But they always bend over backwards to support Windows. This winds up making Windows seems more “compatible”, when in reality the “compatibility” issue is one with the hardware developer, not with the GNU/Linux developers. That said, this is usually not an issue on very ordinary computer hardware and you can often check for the compatibility of your hardware before you buy.
Every OS has its own applications- meaning that on Windows, you can only use Windows applications, on OS X, OS X applications and on GNU/Linux, GNU/Linux applications. So, you may not be able to run your favorite Windows application if there isn't a GNU/Linux version. That said, on GNU/Linux there are always options. You can probably run that Windows application in WINE or through virtualization.