Because of Apple’s new Gatekeeper security feature, you may not be allowed to open programs that you download from the Web if you’re running Mountain Lion (OS X 10.8).
You can change those app settings in System Preferences> Security & Privacy> General, but if you just need to let one program through, you can right-click or Control-click on its icon and choose Open from the contextual menu. Doing so will let you temporarily bypass the security setting without adjusting your preferences.
For more information, check out Melissa Holt’s article at The Mac Observer here.
Jay Nelson is the editorial director of PlanetQuark.com, and the editor and publisher of Design Tools Monthly. He’s also the author of the QuarkXPress 8 and QuarkXPress 7 training titles at Lynda.com, as well as the training videos Quark includes in the box with QuarkXPress 7 . In addition, Jay writes regularly for Macworld and Photoshop User magazines and speaks at industry events.