A couple of weeks ago, during Apple Expo in Paris, VMware announced the of a new version of Fusion, their virtualization software for running Windows on Intel-based Macs. As soon as I saw the announcement I downloaded the beta, and I briefly considered writing it up as a news item for TidBITS. But I decided against it, just as I'd decided against writing up Parallels' announcement from a couple of weeks previously about their  to Parallels Desktop - build 5160, still officially called version 3.0 (as was the previous version). In both cases the new releases were moderately interesting and useful, but having reported every new version from both sides for a while, I began to feel my personal threshold for newsworthiness rising. This competition between the two products will surely continue for a long time, and I fully expect that every month or so, one side or the other will tout their latest volley, even if only in a beta release. Major version updates (as opposed to betas or unnumbered feature updates) seem to be news, as do any revolutionary changes that are announced in intermediate versions. But all those releases in between - not so much.
Virtually News -- Lest you think I've suddenly become blasé about virtualization, nothing could be further from the truth. I am delighted about both products, and I think the strong rivalry between these two giants can only be good for consumers - we'll get better software, more choice, and maybe even lower prices. I also remain convinced that for most people, virtualization is a way better solution than using Boot Camp. All I'm saying is that Parallels Desktop and VMware Fusion are still, all things considered, pretty evenly matched, and until one or the other definitively pulls ahead, I'm not going to get terribly excited (or depressed, as the case may be) when I see small feature changes.
Some readers will surely take exception to my claim that the two products are evenly matched, and of those, some will insist that Parallels is better while others will insist, with equal fervor, that Fusion is superior. Which more or less proves my point. I've read comparisons of the two programs on various Web sites, and of course I've used them enough in writing "" to form my own opinions. In a nutshell: Parallels currently has the edge in usability and convenience features; Fusion currently has somewhat better compatibility and raw performance. But these statements are only approximations of the truth. For example, although Parallels may be measurably slower than Fusion in some tasks, it's faster in others - and those others may be the ones you happen to care about. Benchmarks aren't always as objective as they appear, and those I've seen so far don't reflect the real-world tasks people most commonly use these programs to perform. Similarly, although at the moment Fusion lacks some of the spiffy user interface niceties of Parallels, those features may or may not turn out to affect your day-to-day work or play. Besides, every new release potentially changes the equation, so side-by-side testing is typically valid for only a few weeks.
Honestly, either program is a perfectly good and safe choice for almost anyone. (A couple of noteworthy exceptions: if you want to run the 64-bit version of Windows Vista, or if you must use a Windows application that requires direct access to more than one processor or core, Fusion is your only option for now.) You can bet that whichever one you buy now will pick up the features that currently make its rival seem appealing - more likely sooner than later. Likewise, either way, you'll have a better user experience and a more powerful tool in six months or a year when the product has been updated a few more times.
But About Those New Releases -- The latest versions of each program do, as I said, contain some useful changes, even if they don't ultimately tip the scales one way or the other. Parallels Desktop build 5160 (released 11-Sep-07) added mirroring between the Mac and Windows Desktop, Documents, and media folders; the capability to switch audio devices without restarting Windows; iPhone sync support in Windows; improved visual effects for the Coherence mode; updates to Parallels Explorer and Parallels Image Tool; and a variety of bug fixes and performance improvements. VMware Fusion version 1.1 beta (released on 25-Sep-07) provides preliminary, "experimental" support for DirectX 9.0 3D graphics; iPhone syncing with Outlook in Windows; several improvements to Unity mode; better recognition of Boot Camp partitions in some cases; improved support for running under Leopard; support for using the Eject key to eject optical media attached to the Windows virtual machine; several localizations in a single application package; and of course the obligatory assorted bug fixes and user interface tweaks. In short: all nice things, though almost certainly not the killer features you may have been waiting for from either side.
The Battle Rages Lightly On -- I've had long talks with representatives from Parallels and VMware, and both companies tell me they couldn't be happier to have the other as competition. During Apple Expo, I met with Serge Robe from VMware, and one of his colleagues showed me a cell phone picture taken the previous day - it showed Ben Rudolph (Parallels' Director of Corporate Communications, with whom I met the following day) holding a bumper sticker reading "I (heart) VMware." Good stuff.