There are lots of open source desktop virtualization software options out there, but Oracle VM VirtualBox remains ahead of the pack. This open source VDI software provides an entire data center virtualization approach, while other -- equally viable -- products target more specific needs.
VirtualBox is a hosted platform for desktop and server virtualization. It's free and open source and is similar to products such as Microsoft Virtual PC and VMware Player, Workstation and Fusion. For now, it leads the open source desktop virtualization software market, but other open source VDI products aren't far behind.
Here's a look at how open source desktop virtualization stands in 2012:
VirtualBox remains de facto choice
Few who have been following open source desktop virtualization software options would be surprised to find that VirtualBox remains at the top of the heap, and for plenty of good reasons.
The quality of VirtualBox's desktop virtualization software has remained solid since Oracle acquired its previous owner, Sun Microsystems, in 2010 -- something many people (myself included) were worried about. Oracle revises VirtualBox constantly and has kept current with each revision of major operating systems, -- including Windows 8.
What is it that's made VirtualBox such a continuous success in the open source desktop virtualization market? For one, it covers the vast majority of the functionality needed for a virtual machine (VM) on the desktop: a broad array of operating systems, virtualization for multiple cores, multiple monitors, flexible networking (both guest-to-host and guest-to-guest), VM cloning and disk utilities, scripting extensions, command-line support, snapshotting and more.
In addition, Oracle's desktop virtualization software feature set remains competitive. The vast majority of the pieces you need are there, and they work very well. The few things missing from this picture -- physical-to-virtual conversion, for instance -- aren't very relevant to desktop users. Oracle added others only recently, such as VM cloning. Still, VirtualBox has a strong-enough feature set to compete with the likes of VMware Player, VMware Inc.'s free hosted virtualization product. Player's main attraction over VirtualBox remains performance, but the differences between the two options for desktop virtualization software continue to narrow with each revision.
Open source VDI customers are also attracted to VirtualBox licensing and usage terms. The core code is licensed as GPL v2, and its binaries are licensed under Oracle's custom Personal Use and Evaluation License. The latter allows you to use VirtualBox without charge for personal or academic use, but it requires a license for corporate deployment, and redistribution of the binaries under your own auspices is forbidden. That makes it possible for most people to simply grab the precompiled binaries and run them. The few cases where you would need a paid license involve wide-scale commercial reuse -- something not likely to be an issue for most people who just want a free VM for their desktop.
Other open source VDI: Less suited to the desktop
The rest of the products in the open source desktop virtualization software space tend to address more specific needs, rather than the general-purpose approach of VirtualBox. That doesn't automatically make them inferior open source VDI products -- they're merely built to address different needs, not all of which are suitable for ordinary desktop end users.
QEMU, for instance -- a project that is the original embodiment of some technologies used in VirtualBox -- recently hit version 1.0 after being in development for a number of years. QEMU is mainly for developers and programmers, though, because it's designed to emulate multiple hardware platforms -- not just the x86 processor branch, but also PowerPC, PowerMac, ARM, SPARC and other chipsets. That makes it less a desktop system and more a processor system.
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In other words, QEMU is meant more for those who want to work with processor-level emulation rather than boot to different operating systems in a protected environment. You can certainly do the latter with QEMU, but VirtualBox has more, friendlier end-user tools to that end.
Bochs is a little closer to a desktop environment than QEMU. It's specifically designed to emulate generic PC hardware, not an open-ended succession of chipsets, so OSes that use common hardware (Linux, DOS, Windows, BSD, etc.) run directly on it with minimal tinkering. On the other hand, its user interface is clumsy compared to VirtualBox. Plus, much of the hardware Bochs emulates is quite old. For instance, the only network cards available are the Novell NE2000 and an Etherboot pseudo-network interface card.
Bochs has found a home among administrators who emulate older DOS-based software, especially games, and who perform OS-level debugging (for kernel drivers, for example), because the emulated hardware can be single-stepped or slowed to an arbitrary speed. But for everyday open source desktop virtualization, it's a bit more ornery than VirtualBox.
The future of open source desktop virtualization
The open source desktop virtualization scene follows the same pattern that tends to appear with most software: A leader emerges with one major rival, and the rest are reduced to bit players. The leader of open source desktop virtualization software remains VirtualBox; the rival is the proprietary-but-free VMware Player.
The rise of another open source VDI contender could cause VirtualBox to fall from its position, but so far nothing's surfaced that comes close to direct competition. VMware Player is a useful fallback for admins who absolutely need what only VMware's applications can provide, but it's not a substitute for customers that need something with VirtualBox's open lineage.
VirtualBox could also fall from the open source desktop virtualization throne if Oracle ever chose to focus its efforts elsewhere. But given that virtualization is a cornerstone of the company's server business, I don't see that happening anytime soon.
ABOUT THE AUTHOR:
Serdar Yegulalp wrote for Windows Magazine from 1994 through 2001, covering a wide range of technology topics. He now plies his expertise in Windows NT, Windows 2000 and Windows XP as publisher of The Windows 2000 Power Users Newsletter and writes technology columns for TechTarget.