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.)
VirtualBox 4 included an interface redesign, making it easier to view and manage your virtual machines. VM displays can now be scaled, so you can reduce a window size by half (for instance) and still see everything that's going on. The ability to limit a VM's CPU and IO time means the program will be less of a drain on your system's resources, and there are a host of other performance optimisations and bug fixes available.
What's new in VirtualBox 5?
- Storage: fixed a regression causing write requests from the BIOS to cause a Guru Meditation with the LsiLogic SCSI controller (5.0.18 regression; bug #15317)
- Storage: several emulation fixes in the BusLogic SCSI controller emulation
- NAT Network: support TCP in DNS proxy (same problem as in bug #14736 for NAT)
- NAT: rework handling of port-forwarding rules (bug #13570)
- NAT: rewrite host resolver to handle more query types and make it asynchronous so that a stalled lookup doesn't block all NAT traffic
- Snapshots: don't crash when restoring a snapshot which has more network adapters than the current state (ie when the snapshot uses ICH9 and the current state uses PIIX3)
- Guest Control: various bugfixes for the copyfrom and copyto commands / API (bug #14336)
- VBoxManage: list processor features on list hostinfo (bug #15334)
- Linux hosts: fix for Linux 4.5 if CONFIG_NET_CLS_ACT is enabled (bug #15327)
- Windows hosts: another fix for recent Windows 10 insider builds (bug #15337)
- Windows hosts: make it work on Windows XP again (5.0.18 regression)
- Windows Additions: fixed performance issues with PowerPoint 2010 and the WDDM graphics drivers if Aero is disabled