What is VMWare Fusion? How does VMWare Fusion compare to Parallels Desktop for Mac?

First announced on August 7, 2006, released in a limited beta version on or around November 3, 2006, and released as a public beta on December 21, 2006, "Fusion" is the codename for VMWare's virtualization solution that allows one to run other operating systems "inside" or "alongside" MacOS X. In much the same way as Parallels Desktop for Mac, VMWare states that Fusion provides:

The ability to simultaneously run any PC OS -- Windows, Linux, NetWare and others -- on Mac OS X. Switch between operating systems by easily tabbing between applications and share data between the two operating systems by dragging and dropping files on the fly -- all without needing to reboot. What's more, you can create virtual machines and run them on other VMware products or run any VMware virtual machine on your Mac.

The blog TUAW published a leaked memo regarding the features of VMWare Fusion on November 3, 2006. Of these features, most are already provided by the shipping Parallels Desktop for Mac, but of particular interest to many, VMWare also promises the following:

• The ability to assign more than one processor, or more than one processor core (when available), to the program to improve performance.
• Access to physical devices from within VMWare, such as "CD-ROM drives, video cameras, iPods, printers, and high-speed disks".
• Support for USB 2.0 devices.
• The ability to drag and drop files between MacOS X and the guest operating system running within VMWare Fusion.

With the release of the public beta, VMWare lists the same features officially on the company website.

In an excellent InfoWorld report, complete with screenshots of the beta of Fusion, the author notes that these improvements are welcome but also wisely questions whether the "drag and drop" feature will be vulnerable to security risks.

On November 29, 2006, when this Q&A was first published, EveryMac.com noted that Parallels Desktop for Mac used a single core on a dual core Mac, did not provide direct access to the physical CD/DVD-ROM drive, did not provide support for devices that require USB 2.0, and required users to share files using Parallels Tools, which is convenient, but not quite as convenient as drag and drop.

However, EveryMac.com also remarked that it was a safe bet that the programmers at Parallels were hard at work adding most, if not all, of the features that VMWare promises to the next release of Desktop for Mac. Sure enough, two days later, Parallels unveiled beta build 3036, with the ability to "drag and drop" files between MacOS X and Windows, the ability to boot from a Boot Camp partition, a slick "coherency" feature to "show Windows applications as if they were Mac ones", improved graphics performance, and a slew of other improvements.

On December 21, 2006, Parallels released another beta that added support for many USB 2.0 devices, CD burning, and Boot Camp partition support, and a few days after that (December 29, 2006), released "Beta 3" (Build 3106) with better Boot Camp and USB 2.0 support, an improved version of Transporter that makes it possible to "migrate your real Windows PC, or existing VMware or Virtual PC VMs to Parallels virtual machines", a new interface, and more.

The betas of VMWare Fusion look quite promising, but Parallels has shown an impressive ability to churn out improvements at a lightning pace. Ultimately, the competition should prove to make both products better for consumers.