Operating System Costs

The single most important decision affecting the cost of a business computing infrastructure is the choice of operating system. What follows is an outline of the issues that should be considered when comparing the total cost of ownership of various operating systems. The operating systems considered are primarily Linux, Windows, NetBSD, FreeBSD, and OpenBSD, Mac OS X, and closed Unix variants.

The Operating Systems

The operating systems compared here include:
FreeBSD, OpenBSD, and NetBSD
Collectively referred to as *BSD, these are Open Source operating systems based on BSD Unix, similar to Linux, with a focus on networking and security.
Linux The most popular open source operating system, used for servers, and increasingly appearing on corporate desktops and laptops.
Windows All versions of Microsoft Windows, the most popular operating system.
Mac OS X The latest operating system from Apple, OS X uses an Open Source core called Darwin which is a BSD Unix derivative. The GUI is proprietary and written by Apple. Note that previous versions of Mac OS are very different and are not covered here.

Hardware and Performance

The choice of operating system will affect the hardware you need to purchase, although the hardware you already have may have some flexibility. It is often possible to change the operating system on existing hardware; nonetheless, the vast majority of all hardware has only one OS installed over its useful life. Windows and Linux often run on x86 hardware, such as popular Intel and AMD processors. Some Unix variants run on specialized hardware, such as Sun Solaris or AIX. Mac hardware and software is also uniquely designed to work together, although Linux can also run on most Apple hardware. There are certain situations in which installing Linux or *BSD on existing hardware may be the best option; a very common case is migrating Windows servers to Linux or FreeBSD. Migration of existing desktop machines is also possible and can be very cost-effective, especially as an alternative to a Windows version upgrade.

Software licensing

Operating system licenses, and licences for other software, can easily surpass the cost of the hardware itself. Linux, *BSD, and other Open Source programs are available at no cost, for as long as you want to use them. Eliminating Windows and Microsoft Office licenses can be a huge savings for many companies, although migration costs may offset this in the short term.

Development

Internal applications development in proceeds similarly on most operating systems, but there are several areas in which Open Source software provides additional benefits. When in-house applications need to interact with existing software, open-source programs provide complete flexibility. Developers can use the source code to understand exactly how the program functions, and if necessary, can modify it to fit into your existing infrastructure. This flexibility is unmatched by closed software, and this is why for development, open-source systems are simply miles ahead. If your complicated software uncovers an obscure bug in an open-source program, you can fix the bug, submit a patch, and the community will thank you. You can then get on with development. If the same situation occurs in a Windows environment, you must work around the bug, and wait for your software vendor to fix it, if and when they decide to do so. The ability to fix bugs in inter-connected software immediately is a huge win for software development projects.

Migrating existing applications from one OS to another can be expensive. If you have complex applications running on legacy Unix systems or on Windows, it usually is not worth migrating those applications to new platforms. When business needs demand that those applications be rewritten or updated, you may then move them to your platform of choice.

Downtime

The unavailability of a critical computer system can be devastating to a modern business. Linux and Unix have developed a reputation for rock-solid stability and extremely high uptime. Windows is generally regarded as being a rather poor performer in this regard. However, all systems go down from time to time for various reasons. The only true solution to minimize downtime is to make every critical system fully redundant.

For the back-end systems that run your business, Linux or *BSD are excellent choices, as they are very reliable and solid operating systems that can run for years without a crash.

Attack Vulnerability

The Free Software development model allows source code to be viewed and bugs fixed by thousands of developers all over the world. This results in security holes being found and fixed with a speed that is unmatched. GNU/Linux and Open Source server software are generally more resistant to malicious attacks than Windows and closed software. Furthermore, the hacker community that produces this software has a long standing commitment to security. Microsoft has a track record of releasing software with fundamental security flaws, such as Outlook and Internet Explorer.