From the earliest days of Mac OS X, various virtualization solutions have made it possible for users of Apple's Mac computers to run Windows and, more critically, Windows applications. These solutions have gotten dramatically more sophisticated in recent years, allowing you to run Windows applications side-by-side with Mac OS X apps. And the one I'm using now, Parallels Desktop 10, is particularly amazing.
Note: Yes, there are other options, including VMWare Fusion and the free VirtualBox. I use Parallels.
Parallels Desktop 10 is so full-featured I barely know where to start. At the most basic level, it works as you might expect: You install Windows to a virtual machine and if you want, you can access that VM in a window with its contained applications, much as you might in a traditional virtualization product such as Hyper-V Client or Virtual PC.
Windows 8.1 virtualized, running in a window under Mac OS X
But you don't want to do that. The point of using virtualization on a Mac is that you're using a Mac but need or want to run one or more Windows applications. Doing so within a virtualized environment in a window "works" but it's not elegant. Furthermore, it forces you to context shift and learn a second OS. So Parallels lets you run Windows applications side-by-side with Mac OS X apps. It lets you integrate those Windows applications with OS X in ways that are useful and delightful. It's really impressive.
Windows apps running on the Mac desktop
But here's the kicker. I've tested various ways of running Windows (and Windows applications) on Mac OS X over a decade-plus, and nothing I wrote above actually surprised me. I already knew that Parallels offered these capabilities. What really blew me away this time around was that the performance and battery life advantages of this solution, when compared to dual booting with Apple's Boot Camp, really puts this over the top. That is, if you're looking to run Windows and/or its applications with the best possible performance and the best possible battery life, Parallels—a virtualization solution, mind you—is superior to the "native" experience of running Windows under Boot Camp.
This isn't just a win-win for Mac users, it's the triple threat. You get better performance. Better battery life. And a native, integrated experience in which Windows applications are simply available alongside your Mac apps. Amazing.
The only downside to this scheme is one that won't impact many people, though it does affect me. See, I actually prefer Windows to Mac OS X, and am not personally interested in running Windows applications inside that OS. I want to use Windows, prefer Windows to Mac OS X. But that won't be the case for most Mac users. And most people who need this kind of solution will want it to work exactly the way it does.
And folks, you're going to be impressed.
First, Parallels lets you install Windows as always, via an ISO file or disk/disc-based media. Or you can additionally migrate an entire PC or data from a physical install of Windows to a virtual machine, which I could see being valuable, though I didn't test that. It officially supports Windows 7 and Windows 8.1, but I suspect Windows 10 will work just fine too given its underlying sameness. I'm using Windows 8.1.
(If you want, you can of course run multiple virtual environments side by side and, as noted, do so in floating windows as is common with virtualization solutions on Windows and elsewhere.)
During the setup wizard, you're asked if you would like to optimize the VM for the most common usage scenarios—productivity, games only, design, or software development—which is obviously a wonderful nicety. (I chose productivity, since my intention would be to run applications like Microsoft Word and PowerPoint.) And you can choose between Windows 8 and Windows 7 modes, which determines whether Modern apps run full-screen and whether you get a Start screen or menu.
But here's where things get truly interesting. You can optionally integrate Windows into Mac OS X, so that the Windows applications you need run alongside your Mac apps. They can be docked in the system Dock and accessed normally. They can take advantage of unique OS X features like full-screen mode. They integrate at a deep level, too, so you can cut and paste between Windows and Mac apps and even use common OS X keyboard shortcuts—like CMD + C for Copy—so you never need to context shift. You can even use Mac trackpad gestures in Windows applications. Those applications look a bit different from those on the Mac, of course, but Windows apps pretty much work like Mac apps under Parallels.
Word for Windows (in the back) running side-by-side with two Mac apps, OneNote and Maps
The big feature is here called Coherence, and it provides the full-screen integration, but also the ability to put Windows system tray icons right in the OS X menu bar. It's one big happy family.
Word for Windows running in OS X Yosemite's full-screen mode
If you use Boot Camp on Windows, you know the issues. (If not, please do check out my article Windows + Mac: Boot Camp.) Apple doesn't provide optimal Windows drivers, which harms both battery life and performance. And of course, the general issue with any dual boot scenario is that your computer can only be in one OS at a time.
Previous to Parallels Desktop 10, the issues with virtualization were similar, in that performance and battery life were less than ideal. But I can confirm that both are dramatically better with this release and both are in fact better than under Boot Camp. So if what you care about is using Windows, you're still better off using Parallels. I don't know how they did it, but this is a game changer.
To be clear, I'm not using a particularly high-end system. Yes, my MacBook Air is new to 2014, but it utilizes a low-end, mobile-oriented Core i5 chip, and isn't a desktop monster. I did bump up the RAM to 8 GB, however, which is probably prudent if you know you're going to use any virtualization.
And if you're using the latest Mac OS X release, Yosemite—which you pretty much are, since Apple makes it both free and easy to upgrade—then you can use new Yosemite features in Windows too. You can call numbers on your iPhone by clicking them in IE, for example. Share documents, images and other files from Windows applications using OS X accounts for Facebook or Twitter. And even use the Windows 8.1 Start screen as a Launchpad-style UI that sits on top of the Mac OS X desktop for application launching.
And I'm just talking about some of the new stuff here. Beyond the basics, Parallels is a mature virtualization solution that supports virtually (sorry) any functionality you may need.
Ultimately, the only real hardship here is Windows. In addition to purchasing Parallels Workstation 10—just $79.99 new, or $49.99 for the upgrade from previous versions, or a special deal for students—you need to purchase Windows, which can be quite expensive. A 64-bit Windows 8.1 System Builder OEM DVD is currently $92 on Amazon, which looks like the cheapest version, or you could go for the $105 retail packaging, which has both 32-bit and 64-bit installer.
Whichever you choose, Parallels Desktop 10 is awesome. If you need to run Windows applications on your Mac, especially newer applications, this is the way to go. Highly recommended.