Wineskin Winery is a free, open-source tool for running uncomplicated Windows apps in a window under OS X. Based on the free Wine (Wine Is Not an Emulator) software, Wineskin Winery automates the process of wrapping up a Windows app so that it runs more or less like an OS X app. If the Windows app that you want to use in OS X is simple and straightforward—for example, a text editor, small-scale database, or other special-purpose app—you may not need to spend money and time setting up a full-scale Windows environment using Parallels Desktop 11 or VMware Fusion 8. Just wrap it up in Wineskin Winery and launch it in the same way you would launch any other app on your Mac.
Judging from the posts in the Wineskin support forum, most users use the software for playing Windows-only video games, but it's equally useful if you have old Windows apps that you want to keep using even on a Mac. For example, I use Wineskin to run my ancient Instant Recall contacts app. I've also used it to wrap a Windows-based card-playing app for use on the Mac, so that a friend could continue to use her favorite game app.
One advantage of Wineskin Winery is that it creates fully self-contained packages that you can share with other Mac users. One disadvantage is that you won't be able to print from your Windows app as you can from Parallels or Fusion—though really determined Mac users can figure out ways to save printer output from a Wineskin wrapper to a file on OS X and then send that output to a printer. I've done it, but it took a lot of effort.
At the heart of Wineskin is Wine, a long-term, actively-developed open-source project that creates non-Microsoft software for running Windows applications on Linux or the Mac. It's still a work in progress, and it has the fewest problems with apps that run under older Windows versions like Windows XP. The only guaranteed way to find out if your app will run under Wine is to try it out, and fortunately, Wineskin Winery makes the process painless.
Wine and Wineskin Winery are both brilliantly written apps, but they can't run large-scale Windows apps such as Microsoft Office—you'll need Parallels or Fusion for that—and you'll have to be prepared to put in some effort to get them working. If you're on a budget, you might also try Oracle's Free VM VirtualBox, or the security-minded and reasonably inexpensive Veertu, but the latter two options will require more work and run more slowly than the former two. Note that you don't need Wineskin Winery to use Wine under OS X, but Wineskin Winery lets you avoid all the expert-level configuration that you would need with Wine alone.
Wrap an App
I'll walk you through the process of wrapping a Windows app in Wineskin, using the example of UltraEdit from IDM Software, which is by far my favorite Windows text editor. I still use an older version of UltraEdit, but the same basic steps apply to any Windows app that runs in a Wineskin.
Start by downloading or copying your Windows app's installer to your Mac; if you can't get the installer, copy the whole folder that contains the program in your Program Files folder in Windows. Next, download Wineskin Winery from wineskin.urgesoftware.com, and run it. Click the Create New Blank Wrapper button, and give the new wrapper a useful name; I chose UltraEdit. Click Cancel on the prompts that offer to download Mono or Gecko (if your Windows app needs these libraries for displaying HTML data, it will prompt you when you run it). Click View Wrapper in Finder, and quit the Wineskin Winery. Your new wrapper will appear in a Finder window.
Now things get slightly tricky. Don't double-click on your newly-created wrapper. That won't open it. Instead, Ctrl-click on it and choose Open. Click Install Software, then Choose Setup Executable, and navigate to the installer for your Windows app. (If you don't have an installer, choose the option to copy a folder into your Wineskin.) Let the installer run—which it will do as if it were running in Windows. Your installer will offer to set up your Windows app in a folder in Drive C:, which is actually a folder deep inside your Wineskin wrapper. Install your app as usual. The installer will act as if it were being installed on drive C: of a Windows computer.
If Wineskin prompts you to "choose executable," that means it can't figure out what the main program file is in your app; select it from the dropdown list, then select Advanced from Wineskin's menu. Click on the Test Run button and make sure that everything is working. You can make dozens of minor adjustments from the Advanced dialog if necessary, and you can choose whether to run your app full-screen or in an OS X window. If you want to give your app access to specific folders on your Mac, go to the Tools tab, click Config Utility, and specify drive letters that your Windows app will use when accessing your folders.
That's all there is to it. You can now drop files on your new app and open them in the Windows app. One thing to keep in mind is that instead of pressing the Alt key as you do in Windows, you'll need to press the Command key on your Mac's keyboard. You can find other hints and advice in the user forum at Urge Software's web site. And for expert users, there's a fix for the Alt-key problem here.
A Wineskin-wrapped Windows app starts up more slowly than most OS X apps, because the whole Windows-compatible framework has to load before the app itself opens, but after that, the app works at the speed you'll expect—and just as fast or faster than it does under Editors' Choice apps VMware Fusion or Parallels Desktop, and much faster than under the freeware VirtualBox or the minimalist Veertu virtualization app. Wineskin Winery is free, flexible, and ingenious, and it may be all you need to get your Windows apps running on your shiny new Mac.