Oracle VM VirtualBox is an industrial-strength open source virtualisation tool that makes it easy to create virtual machines (VMs), simulated computers that run on your PC but act as though they were separate systems. It's a powerful capability that has many different applications.
If you'd like a closer look at Windows 8 before you upgrade, for instance, then you could install Microsoft's latest in a VM, then access it in a window on your XP or Vista desktop.
Or maybe you've upgraded to Windows 8 and find a favourite old app doesn't work any more? Create a Windows XP VM and you might be able to run it again.
VirtualBox can also be a useful security tool: if you download and test apps in a VM, then any malware you might encounter will be isolated from your main system.
And it's the perfect choice if you want to try out another operating system with the minimum of hassle. Right now you can install Google Chrome OS, all the mainstream Linux variants (2.4 and 2.6), OpenBSD, OS/2, ReactOS, SkyOS, DOS, and just about every version of Windows there's ever been. (Of course you'll need to have the system discs to hand.)
Note that Portable-VirtualBox will enable you to take the VirtualBox installation file, extract the contents and turn this in to a standalone portable application. This is not a portable version of VirtualBox, just a creation tool.
Verdict:
Use this tool to make VirtualBox a standalone portable application you can take with you on a USB key.
Your Comments & Opinion
Run a virtual operating system on your Mac
Host and run a virtual operating system on your computer
Test virtual operating systems
Host a virtual operating system
Run another operating system, seamlessly, on your Mac
Minor update to the popular email client, but with a limited number of new features
Tired of Firefox's rapid release schedule breaking extensions? Firefox ESR is here to help
Cut down on repetitive typing - and typos - with this versatile keyboard macro tool
A powerful portable tool for detecting, benchmarking and monitoring your PCs hardware
The latest stable Chrome Portable includes a number of under-the-hood improvements