If you’ve got a fast Internet connection, a recent Mac, and US$29, what’s stopping you from downloading the just-released 10.7 Lion upgrade to Mac OS X? For many people, what stops them is being unsure whether the software they have is still going to work. In this article I’ve collected various reports I’ve run into around the web.

For an in-depth analysis of Lion itself, including less obvious changes Apple made under the hood, see the Lion review by John Siracusa at Ars Technica—as excellent and detailed as his reviews typically are. And Macworld has published an article about various kinds of incompatibilities you might run into with Lion, including the end of support for PowerPC applications which I talk about at the end of this article.

(Note: Since I wrote this article I’ve upgraded to Lion, and like many people I have been running Creative Suite 5 and Creative Suite 6 very successfully in production except for the known issues listed below.)

Adobe applications

Adobe Creative Cloud, current versions: It isn’t possible to install or run these on Mac OS X 10.7 Lion. As of 2019, the only versions of Creative Cloud applications available for installation are the current version and one previous major version, and those won’t work because support for Mac OS X 10.7 Lion was dropped several years ago. If you want to know the current system requirements, look them up for the specific Adobe application you would like to use.

[Note: The rest of this section was originally written about the Adobe software available at the time Mac OS X 10.7 Lion was released.]

As far as Adobe software such as Photoshop, the Creative Suite, and Lightroom, you can read a page that Adobe has published listing the problems they know about:
Known Issues with Adobe products on Mac OS 10.7 Lion

Jeff Tranberry of Adobe also posted some additional comments on his blog:
Photoshop and Lightroom compatibility with Mac OS X 10.7 Lion

Anecdotally, the word is that Photoshop seems to work fine (except for droplets) as far back as CS3, the first Intel-native version. For Lightroom, the Adobe page above states that Lightroom 2.7 and later are verified to work on Lion.

Full screen mode: People are asking about support for Lion full screen mode in apps such as Photoshop. On his Twitter feed (see tweet 1 and tweet 2), @dhowe (Director of Photoshop Engineering David Howe) explained that in Lion, full screen mode is like putting a document in its own Space. This has some important implications. In the full screen mode that Photoshop has used for years, you can press the Mac standard Command+` keyboard shortcut to switch between open documents, but in Lion full screen mode, you can’t. I tried this out in a few of Apple’s own apps such as Safari, and it’s true. I did find that in apps that support Lion full screen mode, you can switch between documents if you use the Control+arrow key shortcut which is also used to switch Spaces; in other words, Lion seems to lose the traditional distinction between switching Spaces and documents. For some this might be confusing, others may see this as simpler. Also, I can’t find an Apple keyboard shortcut for Lion full screen mode, while Photoshop provides a full-screen keyboard shortcut you can customize. (Update: Many Lion apps use Ctrl+Cmd+F to enter and exit Lion full screen, and some apps will exit full screen with the Esc key. You can customize the shortcut using the Mac OS X Keyboard system preference, but because it’s system-wide, some apps may use a conflicting shortcut.)

There are reports that the Apple implementation of full screen is not ideal even with Apple’s own Aperture, where if you have multiple monitors, you only get to use Aperture on one of your monitors, while the others get the blank Lion “gray linen” backdrop. Similarly, in Safari full screen mode, browser windows only get to live on one monitor, even if you try to drag them to another (it snaps back). Apple Preview and QuickTime Player at least let me maintain palettes on my second monitor while in full screen mode, but documents still only get to appear on one monitor. Even Macworld has similar complaints about Lion full screen mode. It increasingly looks like what Apple really means by “full screen” is “full single screen,” as in an iOS-style presentation.

Given all that, I don’t have a problem with Adobe holding back on Lion full screen support until Apple brings the feature up a couple notches, so that at least we don’t lose the features we have with the Adobe full screen mode.

Note: In OS X 10.9 Mavericks, Apple is changing how full screen apps work on multiple monitors. This may solve the current issues.

Flash Player: There were some early reports that hardware acceleration for Flash is disabled in Lion. This is not true; it was based on a test with a late beta version of OS X. In the actual shipping version of Lion, Flash hardware acceleration works fine.

Other applications

Some other compatibility notes I’ve seen:

• Photography Bay has their own nice roundup of application compatibility under Lion. That’s also where I learned that Nikon software support for the new Mac system will be as poor as it always has been in the past, especially if you own a Nikon film scanner. I run my Nikon CoolScan with Vuescan, which is always kept current for Mac OS X, Windows, and Linux.
• Canon digital SLR software: Canon has begun testing their software with Lion, according to Rob Galbraith. (Update: Canon EOS Utility now supports Lion.)
• Epson pro photo printers: Read the Lion support page on the Epson web site and the Lion FAQ page before installing/updating printer drivers in Lion!
• Color management: Chromix has put together an helpful article and list of color management-related applications, their status for Lion, and the upgrades you’ll need to replace them. Some people are not happy that an expensive paid upgrade will be required to keep using some X-Rite hardware like my Eye-One with Lion…I’m thinking about what I want to do there.
• DiskWarrior: Version 4.3 is compatible with Lion. It came out in March and there’s a free updater if you own DiskWarrior 4.0 or later.
• Microsoft Office: Here’s the Microsoft article about known issues in Microsoft Office 2011. Older versions of Office, particularly those based on PowerPC code, may not run.
• Everything else: Curious about an application not mentioned here? Check the  OS X compatibility tables maintained by Roaring Apps.

You might have noticed that some companies are just now starting to test with Lion. Some people are always surprised by this, but the fact is, a lot of companies only want to spend their limited resources testing with the final shipping version. More than one company has been burned by testing with pre-release software, announcing that everything is fine on the day the final version ships, but then getting customer complaints that the software actually doesn’t work…because something changed in the final version. The Flash misunderstanding above is one example of how having a prerelease copy didn’t accurately represent the final version. Many companies just want to test once, at the end.

Note that there’s a distinction between whether an application will run, and whether it’s going to take full advantage of all of Lion’s features, such as full screen mode, automatic saving and versions. Expect most software to require an update at some point so that you can get the most out of Lion. Some Adobe Mac apps have already had features that are just now coming to OS X (full screen modes in Photoshop and Lightroom, auto-save in Premiere Pro, resize windows from any edge, etc.), so they’ll have to work out how to transition them into the Apple versions of those features, if that’s what they decide to do.

Old PowerPC applications

Because Lion only runs software made for Intel CPUs, software that runs only on a PowerPC CPU (such as a G4 or G5) will not run in Lion. Some color calibration software falls under this category. If you’re not sure if you still have any PowerPC software, while you’re still in Mac OS X 10.6 Snow Leopard open System Profiler; you can get there by clicking the Apple menu and choosing About This Mac, then clicking More Info. Then in the left panel click Applications, and in the right panel sort the list by Kind. Anything listed as PowerPC or Classic won’t run in Lion; if you still need those applications you’ll want to find updated versions of them.

In my case, the X-Rite Eye-One Match software for my monitor calibrator, shown above, is just one of many PowerPC applications that won’t work in Lion. Some of the others are AppleScripts I need to recompile, others are firmware updates and really old apps I never got rid of (the Glider Pro game, Sync apps for my old PalmPilot). The System Profiler test isn’t conclusive; as with many major system upgrade, some applications may have their own specific issues with Lion even if they meet the basic requirements for compatibility. Those applications will need to be updated by their developers.