Introduction

Microsoft Windows remains the dominant desktop operating system with approximately 90% of the client operating system market. If Microsoft's monopoly is ever going to be challenged by Linux, there has to be an easy way for Windows' users to be able to learn about this rival operating system. However, it would be naive to think that a Windows user is going to wipe their Windows partition, write off their years of Windows computing knowledge and install Linux just to see if it has more to offer.

Whilst there are so many different ways for users to try out Linux, most of them suffer from barriers for newcomers to Linux. The obvious way of trying Linux is to install it to a spare machine. However, this is not going to be feasible for many users, not least because it may seem to be an indulgence to use a second machine to tinker around with a different operating system, or will require some outlay which hardly can be justified in the current economic conditions.

Live CD/DVDs Linux distributions do not require a second machine, but do not necessarily make a great environment for learning about Linux. Besides the fact that this type of media can never match the speed of a hard disk based installation, it is likely that a Windows user may need a specific application that is missing from Linux. Over time the user may come to learn to do without that software (e.g. Linux has equivalent software which has the same, or similar functionality, or the individual learns how to run the Windows application under emulation). However, the newcomer to Linux may get frustated and scrap Linux altogether long before giving it a real chance to shine. It's a similar scenario for running Linux from a USB drive. A different approach is taken by Wubi. This software allows a user to install a specific Linux distribution (Ubuntu) to the hard disk as any other Windows application, in a simple and safe way. But whilst this Ubuntu installer does not require modifications to the partitions of a PC, does not install special drivers, runs quicker than from a CD/DVD, and lowers the barriers to entry considerably, again it does not let the newcomer try out Linux and Windows at the same time.

Equally, the age-old method of partitioning and multi-booting a computer has the same difficulties, but also the added danger that the repartitoning may go horribly wrong, and leave the user without a functioning Windows operating system. Many users will not take that risking their production operating system in this way.

The focus of this article is to evaluate applications which let users run Linux and Windows at the same time on a single Windows machine. The user can therefore become accustomed to Linux, learn all about it, yet retain the familiary of their Windows environment. This provides a gentle transition to the Linux world. As the user becomes more familiar with the vast range of software available under Linux, he/she may become progressively less dependent on Windows, and come to rely more on the huge range of quality open source applications. One day the user may then take the plunge, run Linux natively, and experience the real power that Linux offers. Utopia.

This article is not intended to be an exhaustive survey of the different ways of running Linux under Windows, but instead represents eight of the best ways of concurrently running the two operating systems without additional charge. Other software which could be used includes Bochs, Topologilinux, Fedora coLinux, and coSARA, but we consider they are not the best options available. Another way of running the two operating systems at the same time is to use remote desktop software, such as NX client, or VNC, and run graphical applications remotely on a Linux server, while being displayed on the local Windows desktop. Of course, this approach has many disadvantages, the least of which it is unlikely to be a free solution.

Virtualization is the current boom in the software field. Each virtual machine has its own share of CPU, memory, network interfaces etc which is isolated from other virtual machines. This article selects the best no-charge virtualization software.

So, let's explore the eight applications at hand. For each Windows application we have compiled its own portal page, a full description with an in-depth analysis of its features, screenshots, together with links to relevant resources and reviews. We whittle these eight software packages down to the best four in the final thoughts page.

Read ahead:

• Portable Ubuntu for Windows
• Cooperative Linux
• VMware Player
• VMware Server
• VirtualBox
• Virtual PC
• QEMU
• Cygwin
• Final Thoughts

Last Updated Sunday, July 03 2011 @ 10:34 AM EDT