However, there is another option - called 'virtualisation' - that allows you to run Mac and Windows apps together at the same time. There are two main virtualization programs available for the Mac - Parallels Desktop 11 and VMWare Fusion 8 - both of which have just received major updates to support the new El Capitan version of OS X, as well as the recently-released Windows 10.
VMWare has a background in corporate computing, and didn't seem terribly interested in talking to us when we contacted them for this feature, but Fusion is still a fine product so we managed to get hold of the latest version of Fusion in order to see how it matches up to its number one rival from Parallels.
Related: How to install Windows on a Mac using VMWare or Boot Camp | How to run Windows 10 on Mac | Run Windows on a Mac using Virtual Box | Partitian a hard drive on a Mac
Create a virtual machine with Parallels Desktop, VMWare Fusion and VirtualBox
Parallels Desktop and VMware Fusion work in the same way: you create a virtual machine, then install Windows into it.
Parallels Desktop and VMWare Fusion both work in the same way. They allow you to create a 'virtual machine' (or VM) on your Mac, which duplicates the workings of an actual Windows PC. You can then install a copy of Windows - or even other operating systems, such as Linux - onto this virtual machine along with any other Windows apps that you might want to use.
Your Windows virtual machine can run on the Mac desktop just like any other Mac program, allowing you to run Windows software right alongside all your normal Mac apps. This is really useful for running Windows apps that aren't available on the Mac - such as the Access database, which is included in the Windows version of Microsoft Office, but which has never been available on the Mac.
Both programs cost about £65 for a single-user license, although both Parallels and Fusion also offer 'Pro' versions with additional features and multi-user licenses for business users.
VirtualBox is a free alternative into which you can install Windows, Linux and other operating systems.
There is another virtualization program that's worth mentioning. VirtualBox is an open-source program that is available free of charge for personal use. However, VirtualBox is primarily aimed at IT managers in larger organisations, and isn't really the best choice for ordinary home users or individual business users who just need a simple way to run a few key Windows apps on their Mac.
System Requirements for Parallels Desktop, VMWare Fusion and VirtualBox
Virtualisation gives you the best of both worlds, as it allows you to have Windows and Mac apps running side-by-side. But running a virtual machine on your Mac means that you are effectively running two operating systems at the same time, so you will need a fairly fast Mac with plenty of memory and storage in order to get decent performance from your virtual machines. One useful feature of both Parallels and Fusion is that they allow you to configure your virtual machines with different amounts of memory, and you can even assign a specific number of processors to each virtual machine. That's very useful for people who own high-end Macs with quad-core or even 8-core or 12-core processors, as you can assign two or more processors to your virtual machines in order to provide really good performance.
Windows, Wine or CrossOver
CrossOver allows you to run common Windows applications, such as Microsoft Outlook, within the OS X environment.
Parallels Desktop, VMWare Fusion and VirtualBox also require a paid-for Windows license in order to create a virtual machine. However, there is one other option that gets around that requirement. Wine is another open-source program that can be used to run Windows apps on your Mac. But instead of creating a virtual machine that runs the full version of Windows, Wine inserts a kind of 'compatibility layer' between individual Windows apps and the Mac operating system. The advantage of this approach is that it doesn't require a copy of Windows, nor all the extra memory and processor power that you need to run a virtual machine. The downside is that Wine isn't compatible with all Windows apps, so you'll need to check the Wine web site (www.winehq.org) to see if it will work with the Windows apps that you need to use.
Wine is also pretty complicated to set up and use, although there is a paid-for version called CrossOver that gives the program a more Mac-like graphical interface (www.codeweavers.com). Even so, we'd still only recommend CrossOver to people who don't mind a bit of tinkering in order to get it up and running properly. Fortunately, CrossOver, Parallels and Fusion all offer trial versions that you can check out before buying in order to see which one suits you best.
Getting Started: Setting up Parallels Desktop or VMWare Fusion
Out of those four programs it's really only Parallels Desktop and VMWare Fusion that we'd recommend for most Mac users. You do have to pay for them - as well as paying for a copy of Windows too - but they work very well and give beginners plenty of help to get started. Parallels Desktop perhaps has a slicker interface, but the two programs work in basically the same way and offer the same core set of features.
When you launch Parallels or Fusion for the first time they both present you with a 'wizard' - a control panel that provides a step-by-step guide to creating a virtual machine on your Mac. The main option for most people simply will be to create a virtual machine that runs Microsoft Windows. Both programs allow you to insert a Windows installation DVD, or to use an 'image file' that you can download from the Microsoft web site. They've both been updated to work with Windows 10, and will go back as far as Windows XP and even the pre-Windows MS-DOS operating system too.
If you're already using Boot Camp to run Windows on your Mac then both Parallels and Fusion will also allow you to quickly convert your existing Boot Camp partition into a virtual machine.
Running Linux and other operating systems in Parallels Desktop or VMWare Fusion
Windows isn't the only option for creating virtual machines, either. For Linux fans, Parallels and Fusion both allow you to create virtual machines that run various versions of Linux. You can even create a virtual machine that runs OS X itself - which can be really handy for trying out things like the beta version of El Capitan, or for developers who want to test their software on a safe virtual machine that won't affect any of their important work files. There are a couple of differences here, though.
For some users, the choice of operating systems that you can use on your virtual machines may make the difference between buying either Parallels or Fusion. Parallels Desktop can create virtual machines using Android and ChromeOS, which will be really useful for developers of mobile apps, while Fusion sticks to its corporate computing roots by supporting the old Netware operating system that was used by many large organisations in the past.
Full-Screen Windows with Parallels Desktop or VMWare Fusion
Parallels Desktop running Windows 10 full screen
When Parallels and Fusion were first developed they would display the Windows desktop within its own window on your Mac desktop. Any Windows apps that you wanted to run on your virtual machine would then appear in their own window-within-a-window, which could be a bit of a wrench for your brain at times. So, over the years, both programs have developed ways of more smoothly integrating Windows apps into the Mac environment.
If you spend a lot of time working just with Windows then both programs will allow your Windows virtual machine to expand into full-screen mode. The Windows desktop will fill the entire screen and hide the Mac desktop altogether, so that it looks and feels just like using an ordinary Windows PC - although you can still switch back to the Mac desktop at any time just by using the standard Command-Tab keyboard shortcut.
But most people will probably prefer to switch back and forth between Mac apps and Windows apps, so a better solution is to hide the Windows desktop altogether and simply display individual Windows apps floating on the Mac desktop so that they look just like ordinary Mac apps.
Unity And Coherence in Parallels Desktop or VMWare Fusion
Using VMware without the Windows menu
Fusion calls this option 'Unity', while in Parallels it's called 'Coherence'. There are some minor differences between the ways that each program handles these modes, but they work in essentially the same way. You can copy and paste information between Mac and Windows apps, which makes it easy to switch back and forth between different apps, and you can tell your virtual machine to share Mac folders, such as your Home or Pictures folders, so that your important files are available to Windows apps too.
Parallels Desktop also allows you to integrate Windows apps into OS X
Hiding the Windows desktop also means hiding many important features, such as the Windows Start Menu and the Taskbar, so Parallels and Fusion both add an ingenious pull-down menu to the main toolbar that runs across the top of the Mac screen. These pull-down menus allow you to view many key Windows commands and controls right on the Mac desktop - which is something that still amazes me even though I've been using both programs for years. You can even put individual Windows apps into the Dock, allowing you to launch Windows apps stored on a virtual machine just as you would launch an ordinary Mac app.
Parallels does have a slight edge here, though. When running Parallels, you can use the Mac's QuickLook feature to get an instant preview of files that are stored on your Windows virtual machine. The latest version of Parallels also came up with a headline-grabbing trick by allowing Cortana - the Windows 10 rival for Apple's Siri - to run on Macs even when your virtual machines are hidden or running in the background. So you can just say 'Hey, Cortana' to issue voice commands to Windows 10 even while you're working in ordinary Mac apps. It's a neat trick - especially since Apple itself hasn't managed to get Siri running on the Mac yet - and the slick presentation of Parallels Desktop may have slightly more appeal for many users, even if the two programs are very similar under the surface.
PC Performance
Be cautious with your Windows setup: if you allocate too large a chunk of the OS X resources to Windows, it's going to struggle anyway - the host computer needs enough memory and hard disk space to operate correctly.
As we've mentioned, running Windows as a virtual machine on your Mac does require a fairly fast processor along with plenty of memory and storage. And even then your virtual machines will never run as fast as Windows using Boot Camp, as they're having to share your Mac's computing power with OS X itself. However, years of fine-tuning have allowed both Parallels Desktop and VMWare Fusion to run fairly smoothly on most recent Macs that have dual-core Intel processors. During our tests we did find that our virtual machines initially started up a little more slowly when using VMWare Fusion, but once the virtual machines were up and running properly Fusion and Parallels produced very similar scores when running the productivity tests in the PCMark 8 benchmarking software.
We wouldn't attempt to try and play and 3D action games using either program, but they can both handle routine productivity tasks, such as running the new Edge web browser or Windows versions of Microsoft Office, smoothly enough that they feel perfectly usable on a Mac. And, if you have one of the more powerful Mac Pro or MacBook Pro models, you may even be able to run some heavy-duty graphics and CAD tools, such as AutoDesk.
Macworld verdict
The smart graphical interface of Parallels Desktop is very attractive, especially to newcomers who may not have used virtualisation software before. In contrast, VMWare's focus on corporate computing may make Fusion seem a little less welcoming for first-time users. Even so, the two programs provide very similar features and performance when running Window virtual machines, and we'd happily recommend them both to anyone that needs to run a few Windows apps on their Mac. However, the slick integration of Mac and Windows features, and headline-grabbing features such as its trick with Cortana means that Parallels wins when it comes to sheer eye-catching presentation.
Read next: El Capitan versus Windows 10