Set OS X & Windows Open With... to Each Other

This was too perfect to change so here it is:

Hack Attack: Set Windows programs as defaults for your Mac (and vice versa)

windows-mac-head.pngMac guy and PC guy can fight for supremacy until the end of time, but there's one simple fact that anyone who's worked on both Mac and Windows knows: Some applications are better on the Mac, others are better on Windows. With the latest version of the Windows-on-Mac virtualization tool Parallels, you can set default applications across platforms, meaning that if there's an application that you prefer on Windows, you can set files on your Mac to always open with the the Windows application (and vice versa). With Parallels, you can create the ultimate hybrid operating system.

For example, let's say you've installed Office 2007 on Windows in Parallels but you're waiting around in 2003 on your Mac. Not anymore. With the latest Parallels, you can double-click a Word doc on your Mac and watch as it automagically opens up with Word 07 via Parallels. With a few very simple steps, you can set up the ultimate Windows/Mac hybrid.

Set up Parallels

As long as you've got a Mac, $80 to buy Parallels, and a copy of Windows, getting up and running with Parallels a cinch. Here's how to install Windows with Parallels. If you want to use your Windows partition in Parallels and Boot Camp, you can do that, too.

Here's your hybrid OS, Dr. Frankenstein

open-mac-in-windows.pngThe unholy union of Windows and Mac got especially exciting when Parallels introduced Coherence, a feature that allows Windows and Mac apps to commingle on the same desktop. Weird? Yes. Useful? Of course!

But the latest and greatest new feature in Parallels is called SmartSelect, and it's what lets you hybrid your desktop so that you can set default applications across Windows and Mac. That means you can always use the best tool for the job, regardless of whether it runs on Mac or Windows.

Set the default application by filetype

open-mac-in-windows.pngSetting up your SmartSelect defaults is as simple as point-and-click. In either Finder or Windows Explorer, right-click (or Ctrl-click) the file you want to open and select Open With. You should see a list of applications, Windows and Mac, associated with that file. If you're doing this in Windows, Mac apps will be named .app (like Firefox.app) and include 'Mac' in parentheses after the title of the program. On your Mac, Windows programs will have the Parallels icon superimposed on the application's icon to indicate that it's a Windows app. To open a file in a different application just once, select the application you want to use to open that file and that's all. Windows or Mac, it should open the file in the program you selected.

change-default-windows.pngTo set an application as the default for that filetype, you just follow the same set of steps you normally would on the respective OS. In Windows, right-click the file and select Open With again, but this time select Choose Program.... Pick the program you want to set as the default and check "Always use the selected program to open this kind of file."

change-default-mac.pngOn the Mac, right-click the file and select Get Info. Toward the bottom of the Info window you should see a section labeled Open with. Select your preferred default from the dropdown and click Change All.... Any file on your Mac ending with the same filetype should now always open with the application you've chosen, Windows or Mac.

Changing default browser, email, and FTP client

change-default-web.pngThe above method should work to change your default application for virtually any filetype, but when it comes to unifying your browsing, email, and FTP clients, you have to take a different but equally simple approach. Just go to the Parallels Desktop preferences and select the General tab. In the section labeled Shared web applications, you can change the default application for web browsing to Open all web pages in Windows, Mac, or in the default for each OS. If you leave it set to Default, you'll end up with different browser windows, for example, running on Windows and Mac. Setting your browser to a specific OS will ensure that all your browsing is unified, a feature I've been dying for from Parallels. The same is true for your preferred email and FTP clients.

Whither and wherefore would I use this?

Like I said above, some applications are just better in one OS than in the other. For me, the short list of such applications goes a little something like this:

Browser: We talk a fair amount about Firefox vs. IE vs. Safari around here, and Firefox normally wins out. But let's get more granular. If I had a choice between Firefox on Windows and Firefox on Mac, I'd take Firefox on Windows hands down. I may be alone on this, but Firefox on my Mac has always been a bit on the buggy and sluggish side compared to Firefox on Windows. Your mileage, as ever, may vary.

Word Processor: There are a lot of good alternatives, but as much as I hate to say it, there really is only one Microsoft Word (for now, at least), and the latest version of Word is only available for Windows. Well, not anymore.

FTP: If I've got to pick my favorite FTP client, it'd have to be the Mac-only Transmit. Smart favorites, droplets, and excellent Quicksilver integration sway my vote toward Transmit for all of my FTP duties.

Text editing: There are a lot of very good text editors for Windows, but I still haven't found an editor I like better than the Mac-only TextMate. It's macros and interface are excellent.

App launching/file manipulation: We love Launchy, but there's only one Quicksilver, and it's only on the Mac. One cool thing about Parallels is that you can launch Windows applications with Quicksilver now, so you really wouldn't need Launchy in this setup at all.

Text replacement: If you're a heavy user of text replacement applications like Windows-only Texter or the Mac-only TextExpander, it's worth noting that these utilities only work with apps running in their respective OS. I (as the biased creator) prefer Texter for some of its more advanced scripting capabilities, but both apps are very good at what they do. Some of my desire to run Firefox and other applications in their Windows variants is influenced by my heavy reliance on Texter in those applications. If you need text replacement in both Windows and Mac apps, you can run both.

I'm very curious to hear which combination of Windows and Mac applications would make up your ultimate hybrid operating system, so throw in your two cents—and any other thoughts—in the comments.

Adam Pash is a senior editor for Lifehacker to whom OS monogamy is out of the question. His special feature Hack Attack appears every Tuesday on Lifehacker. Subscribe to the Hack Attack RSS feed to get new installments in your newsreader