In the dedicated server world, there has been a long standing rivalry between Microsoft Windows and Linux.  The desktop market has been different, with Windows having had many years to refine itself.  The first version of Windows was released in 1985, and by the 1990 release of Windows 3.0, there was no looking back (and perhaps no catching up), and the Microsoft juggernaut has totally dominated the desktop market since that time. The Linux story began in 1991 with its first version under GPL being released January 1992.  

Comparing Windows and Linux is a complex task as both these labels encompass several individual operating systems. By Windows we refer to a whole set of operating systems (like Windows 98, Windows XP, Windows 2003 Server) that have been developed by Microsoft. The word Linux is used to refer to any of several operating systems which include the Linux Kernel. These distributions are developed by various vendors (Red Hat, Novel, Canonical etc) and different programming models.  See our whitepaper on Linux Distributions for further information. There are different flavors of both operating systems for desktop and server use. We have evaluated them in both these categories and on various criteria. 

Desktop Usage
While it may seem odd to include desktop usage in an article focused on dedicated server users, more and more dedicated server clients run remote desktop applications on their servers, making desktop functionality critical to their operations. If you're not interested in desktop functionality, click here to jump to the server comparison.

The desktop market for personal computers has long been dominated by Windows. Various efforts have been made over time to penetrate this market by various Linux vendors. To date, none of these efforts have had any material success. Recent efforts appear to be more credible, with distributions like Ubuntu focusing on making Linux viable for desktop users. Still, it has yet to be seen how successful these efforts will be in the marketplace. Microsoft continues to strongly resist any losses in desktop market share by slashing prices where needed. Let us take a closer look on how the two choices match up.

Installation on a Single Boot System
Traditionally Windows has been trivial to install, with Linux, on the other hand, being considered too complicated to understand and install by the average user.  Recently, however, this has changed, particularly in desktop-friendly distributions like SUSE and Ubuntu. Even more server-oriented systems like Fedora and Centos use the graphical Anaconda installer, which approaches (but doesn't equal) Windows' ease of installation.

Linux in installations do go faster than Windows installations, in general. The average Linux installation takes about half the time an equivalent Windows install takes (on average, one hour for Windows and half an hour for Linux).

One interesting twist is that the full versions of various distributions of Linux can be run directly from a CD, while this is not the case for Windows. A copy of Windows has to be installed to a hard disk in order for it to run.  

Consistency comes into play between the choices. Almost all versions of Windows have similar installation procedures, while each distribution of Linux has a different installation process (although the distributions using the Anaconda installer have some similarity). Given this, installation will generally be easier for a person installing a newer version of Windows than for a person installing a new distribution of Linux.

Overall, the ease of installing Windows still wins out in desktop scenarios.  

Installation on a Dual/Multi Boot System
Dual/multi boot refers to the process of installing two or more operating systems on the same system.  Generally, these systems will prompt a user during the start sequence to select which operating system he/she would like to boot.   Dual/multi booting is enabled by programs called boot loaders, and is most often used in situations where the software of one operating system is not usable on other operating system and the user needs software specific to both operating systems. Dual/multi booting is also popular with software testers and Quality Assurance specialists, as it allows them to easily test their products on multiple operating systems.

Windows enables dual booting with any other Windows operating systems, MS-DOS, and version of OS/2.  A user can multi boot nearly any operating system using FAT or NTFS file systems, although multi-boot systems using NTFS file systems have often been found to be problematic.

Most versions of Linux allow for dual/multi booting. Linux can be easily used alongside various operating systems, including Windows.  It is always advisable to install Windows first and Linux second when configuring a multi-boot Linux/Windows system, as the Windows installer does not accommodate multi-boot Windows/Linux systems. 

Partitioning products are often useful in multi-boot environments.  Several third party partitioning products are available for Windows with a variety of features while there are very few such products available for Linux.

Users – Multiple users and Privileges
Linux is designed from the ground up with multi users in mind, while desktop versions of Windows have minimal granularity when it comes to user rights.  Most desktop installations of Windows are intended to be used by a single person at a time.   All versions of Linux are designed to handle multiple concurrent users.  User rights can be easily defined on both operating systems, although highly configurable security models are only available on those Windows systems that are connected to Windows Server domains.  This situation is similar with file permissions and remote access rights.   On the positive note, Windows scores in ease with which user rights can be administered whereas Linux generally forces such configuration to be done at the command line.

Interfaces
On the desktop, GUIs are everything.  Unlike servers, where web-browser based management is now a highly accepted method of administration, and where SSH, a command-line based system of remote administration similar to Telnet, is often used, desktop systems require some form of GUI.

Microsoft is well known for spending absurd amounts of money on research on the needs and wants of desktop users, and this research is readily apparent in the sophistication of Microsoft user interfaces.  Linux, on the other hand, is developed and upgraded by users themselves resulting in what is often a mishmash of metaphors, often with inconsistent interfaces. 

In every modern version of Windows, a GUI is required, while in most distributions of Linux, it is optional.  Unlike Windows, Linux distributions let you choose between popular GUIs, the most common of which are KDE and GNOME.  Both Windows and Linux offer heavily customizable user interfaces, allowing users to vary text and icon sizes, etc.  This flexibility allows the users to customize the desktop according to their preferences, and often results in some remarkably hideous desktops. 

It is often suggested that Linux is expert friendly while Windows is user friendly.  Realistically, though, the edge in current interface sophistication has to be given to Windows, with Linux still working on equalization.   This may change in the near future, with efforts like Ubuntu resulting in extremely attractive and useful desktop interfaces.

Web Browsing
These days, web browsers are the primary use of many desktop computers.  The sheer market penetration of Windows has made it possible for Internet Explorer to remain the dominant web browser used on the Internet. Internet Explorer provides a stable, robust Internet experience with few surprises.   While security has been a concern in the past, modern versions of IE have have very few vulnerabilities exposed, and Microsoft is extremely quick in patching those that do emerge.  Beyond this, the built-in Windows Update feature of Windows allows users to keep up to date on security patches with almost no effort.

While there are multiple options for browsing with Linux. Mozilla Firefox browsers are approaching dominance in the Linux market.  Firefox has posed the most significant threat to IE since Netscape, and has innovated in several areas such as tabbed browsing.  IE7 has matched most of those feature, however, and recent trends show that adoption of Firefox seems to be slowing.

Application Software
The number of applications available for Windows outnumbers the software titles available for Linux by a huge margin.   Beyond availability, however, the primary difference, is price.  Specifically, most Linux software is free, released under the GPL, whereas most Windows software is commercial and requires payment to the software writer.  The installation of utilities and applications for Windows is generally consistent, especially since the advent of the Windows Installer system.   Conversely, installing software on Linux varies with the different distributions and is generally not as simple for average users.  Programs meant to run on either operating system will not run on the other, hence the need for dual/multi boot systems.   Interestingly, the market for application software is changing dramatically, with a huge shift to web-based applications.  Both Windows and Linux software is generally being replaced wherever possible with browser-based applications that can be accessed over the Internet.

Stability
Linux kernels over time have been generally acknowledged by experts to be quite stable.  The latest versions of Windows (XP onwards) are also generally considered quite stable, while opinions differ on earlier versions.  A built-in firewall is present in almost all Linux distributions. Windows has a firewall built into XP and later versions.  While Windows uses the well regarded NTFS file system, the various Linuxes use several encrypted file systems such as EXT3 and Reiser for enhanced security.  For desktop level security, Microsoft released its first Anti-Spyware product in 2005, which has evolved into Windows Defender in 2006.  This product is free to all correctly licensed Windows users.  There are also many third party offerings, from Symantec's collection of Norton utilities and security products to various other offerings from Mcafee, Kapersky and others.  While reported cases of viruses and spyware are still relatively rare in the Linux community, it is also true that choices for protection against these threats are also rare. 

Bugs / Crashes / Critical Errors / System Halts
Crashes are almost always caused by programming errors of some kind or other, although most experts agree these errors are inevitable with the complexity of modern software, particularly software that has to interact with other products.   Both Linux and Windows have their fair share of bugs, and while both camps like to tell people that the other side crashes more, the truth is that both Linux and Windows can be depended on to crash with some regularity.  The same is true for rebooting.  Neither operating system needs rebooting regularly if it is left to serve websites and process email.   When called upon for interactive desktop work, however, both Linux and Windows appear to need rebooting fairly regularly, failing which odd behavior often results.

Ease of Installing Drivers
Hardware is generally easier to install on Windows than Linux, primarily because hardware vendors design drivers with Windows in mind.  All versions of Windows come with built in drivers for most modern hardware.  Extremely new hardware requires driver installation, which thankfully is trivial in Windows.  Linux fairs quite badly on ease of installing hardware, with an installation process that is much more cumbersome for average users.  It should be noted, however, that many Linuxes can run on legacy hardware, while Windows continues to require modern, well-provisioned systems to run properly.  

Server Use
The server market, particularly the Internet server market, has stabilized somewhat in recent years.  Unlike the desktop market which is totally dominated by Windows, the server market is much more even, with Linux having excellent representation in web/email servers and with Windows continuing to dominate the corporate server market.  In this whitepaper, we will evaluate both operating systems on various key parameters.

Performance and Stability
Both Linux and Windows have reached extremely high levels of stability, particularly in the case of non-interactive servers.  Remote Desktop servers are less stable, generally, often due to bugs in the software used on these servers.  The Windows kernel is, of course, under the control of Microsoft, which maintains tight control and high levels of rigor on the code base.  The Linux kernel remains in the control of Linus Torvalds, which is seen by many as a major weakness of the OS in the event that he is unable to continue his duties for any reason. 

Security
Security is among the most serious issues in the server market.  Most malicious attacks target Windows servers, which has led to a perception that Windows servers are more susceptible to viruses, Trojans and other exploits.  In recent years, the increased number of malware targeting Linux servers combined with the serious effort Microsoft has made to reduce the vulnerability of its servers has resulted in a significant adjustment to that perception.   While IIS and Microsoft Outlook have been significantly more prone to virus attacks than corresponding Apache and Postfix applications on Linux, it is now reasonable to say that neither system poses a huge risk of malware if properly configured and maintained.  It should be noted that Windows has achieved EAL4 standards while no current Linux distributions have achieved this.  Linux security configuration and maintenance depends to a large extent on the distribution being used and availability of expert IT professional to maintain a secure environment. In contrast, Windows Server system administration is relatively easy and Microsoft provides wizards and technical documents to assist in hardening the security framework of Windows Servers.

Web Hosting and Script Handling
To anyone renting a dedicated server, web server software is critical part of the decision. On most Linux servers, Apache is used as the web server.  Windows Server, on the other hand uses IIS (Internet Information Server) for web hosting, and modern version of the OS bundle it in with various other Application Server services.  Both platforms are highly efficient and can handle high-traffic websites without difficulty.  IIS provides support for FrontPage extensions, and while these extensions can theoretically be made available under Linux, many such implementations have proven unreliable.  CGI scripting in the Perl language is better done on Linux in Apache, although support for Perl can be added to the IIS.  Other server side scripting technologies such as PHP and Python are well supported by both operating systems.  ASP and the newer ASP.net are native to Windows, with effectively no support under Linux.  This is also true for the VB Scripting language. 

Licenses
Most Linux distributions are licensed under the GNU General Public License (GPL), version 2. This license requires all distributed modifications to the source code to also be licensed under the GPL. As such, it is sometimes referred to as the "share and share-alike" license. Some other Linux distributions, especially those intended for software libraries, use licenses such as the GNU Lesser General Public License (LGPL) (formerly known as the GNU Library General Public License), which is a more liberal variant of the GPL.  This license is also used by some individual applications, like OpenOffice.org. There is some controversy surrounding the most recent version of the GPL (Version 3), with Linus Torvalds announcing that the Linux kernel would not be released under that license.

Windows, on the other hand, is a proprietarily licensed operating system. Windows has been using various End User License Agreements (EULA) for licensing since its inception. Some versions of Windows have also been using the Microsoft Reference License and Microsoft's Shared Source license. Microsoft volume licensing offers companies (including eSecureData.com) an economical way to buy and manage multiple software licenses. The latest version of windows (MS Windows-Vista) contains strong copyright enforcement and is protected by digital rights management.    

Support
Various distributions of Linux have paid support from their vendors, in addition to unpaid support in the form of user groups, open source developers, mailing lists and news groups. There are various different Linux user groups who cater to the needs of specific distributions and regions.  Many Linux vendors like Ubuntu distribute their distributions for free and only charge for support.

In case of Windows, Microsoft provides full support for its current products. It has a very large technical support division and it also maintains a knowledge base on its website for self support.  It provides both mainstream and extended support for its products. Microsoft also maintains self help solutions in its knowledge base for obsolete products.

Summary
The newer flavors of Windows and Linux are both intent on delivering improved features and performance. While Windows 2003 server has been quite successful in removing apprehensions about the reliability of Windows as a server operating system, Desktop flavors of Linux like Ubuntu have started redefining Linux as an efficient desktop operating system. As has always been the case, the choice of the operating system is more dependent on the particular needs and objectives of the individual application, and the increasing competition gives users a better choice than they have ever had in the past.