When you decide to get a new dedicated server, you will be faced with many software options. You could easily pay big money for a proprietary Unix variant or for Microsoft Windows Server, but there are also plenty of good reasons to go open source. Saving money is just one of them.
Linux and BSD servers are among the most stable in the world. Why else would organizations like CERN rely on open source operating systems like Linux to power their super computers? They have longer uptime, fewer crashes, and better performance than their proprietary competitors.
One could always argue that more viruses and security problems exist on Windows because of its prominence, but Windows is not the number one server OS. Linux, BSD, and other open source operating systems are inherently more secure because of the open source development model.
3. Total Cost of Ownership (TCO)
You often hear about this concept when purchasing a car. How much does it actually cost to buy and maintain your server? With Linux, for example, you can get the OS for free, but you can also get thousands of free software applications. Furthermore, the common development programming languages are more open and offer greater flexibility.
When you start down the proprietary software slope, you place your entire operating at the mercy of your software vendors. If one of them disappears, merges with another company, or simply phases out whatever software you were using, you are left with unsupported and unsecured software or the prospect of having to go through a costly upgrade and conversion process. If an open source project dies, someone else can freely pick it up and continue its development.