How to run Windows apps on Linux

Computerworld - As IT administrators weigh replacing proprietary desktops with open-source systems, they face the question of what to do with their existing applications. One dilemma facing many administrators is whether to replace or somehow keep using those applications. They may be surprised to learn that there is a way to keep using many of the applications they are familiar with, whether they be Windows or Unix-based. In fact, there are many Windows applications that will run well on the Linux operating system.

Why run Windows applications on Linux?

In today's corporate environment, the single biggest issue facing most businesses is cost. Some companies opt to replace their Windows operating systems and standardize on a corporate Linux desktop. However, by doing so, they impose a steep learning curve on their employees, which can sometimes be a painful and costly experience. Instead, a gradual transition makes more sense. Organizations can continue to make users' familiar applications available while they learn the new systems at their own pace, alleviating some of the fear that goes along with learning new programs.

	Opinder Bawa is senior vice president of technology and development at The SCO Group (formerly Caldera International Inc.), where he is responsible for integrating corporate vision and technology strategy. He has close to 20 years of industry experience, including serving as director of IT at 3Com Corp., as well as technology and management posts at Citibank, IBM and Toshiba.

How to run Windows applications on Linux

Windows applications run on Linux through the use of third-party software. This capability does not exist inherently in the Linux kernel or operating system. The simplest and most prevalent software used for running Windows applications on Linux is a program called Wine. It is included with many Linux distributions by default. It consists of a loader, which loads and executes a Windows binary, and a library that implements Windows API calls using their Unix or X11 equivalents. It does not require that Windows be installed on the computer, but will make use of any .dll files it finds. Wine is an open-source program that is available at winehq.org.

There are also commercial solutions available that allow Windows applications to run on Linux. Two of these are Win4lin and VMware. They are different than Wine, in that they require Windows to be installed on the machine along with Linux, and they are not free or open sourced. Win4lin, developed by NeTraverse, only allows Windows applications to be used on Linux. VMware is more advanced and works with many operating systems including Windows, Linux [and] FreeBSD. Both of these work by allowing the Linux and Windows operating systems to run simultaneously, side by side. When a Windows application such as Microsoft Word is running on Win4lin or VMware, it is technically being executed in Windows, which is running simultaneously with Linux. This is different than Wine, which runs a loader that executes the application, but never starts the Windows operating system. For more information on using Win4lin or VMware, see Win4lin.com or Vmware.com. Always check to see if the programs you are using are licensed. If they are, comply with the licenses.