Virtualbox is a virtualization product bought by Sun a couple of months ago. It is free to download, and very very easy to install and use. Other virtualization software include vmware and Xen. Now, why would you need a virtualization product? Imagine that you, like me, are a linux user that really needs/wants to use some Windows Specific Applications, such as Photoshop or Microsoft Office. Or that you are developing an application and you want to test in in several operating systems and/or versions of them. Maybe, you want to test Linux but you are too afraid of f*cking up something in your computer. You could argue that dual-boot is a better option for running some heavy-processing applications, or to play games, and I give you that. However, the pragmatism of having virtually another OS in your own desktop is too sweet to not give it a try. And also, with dual-boot you don’t have the safety of, like in a virtual machine, working in a sandbox that will not affect your host system in any way. /propaganda
Virtualbox has several modes for running, from the basic “run in a window”, like any other program, to a very useful mode called “Seamless”. Seamless is, for the lack of a better definition, having the two operating systems, the host and the guest, in the same desktop as if they were only one. An image is probably better:
Seamless mode allows you to interact with both OS at the same time, without having to switch windows all the time. It’s perfect if you are working with stuff from BOTH OS – e.g. browsing in Linux and writing a thesis in Windows. Furthermore, you can copy paste stuff from Linux to Windows (text and stuff, not files unfortunately) as if they were one. And as for files, you can always create virtual directories to link host to guest and vice-versa.
I just thought I should show this, in my opinion, amazing pearl of software :) It’s being really useful for me at the moment.