Publishers of technology books, eBooks, and videos for creative people
If you're a Mountain Lion user, then you've probably encountered GateKeeper. This is Apple's latest security mechanism, which restricts the apps that can be launched on your Mac. By default, GateKeeper only allows apps to run that are from the Mac App Store, or digitally signed by official developers who have registered with Apple. Try and launch an app from an unknown developer, and GateKeeper shuts it right down. What if you need to use the app, though? Can you launch it without disabling GateKeeper entirely? Sure you can.
GateKeeper's default setting is to allow applications downloaded from the Mac App Store and identified developers only.
Normally, when you try to open an app from an unknown developer, GateKeeper displays an alert message telling you this is risky and isn't allowed.
GateKeeper's default alert when you try to open an unsigned app.
As a workaround, Control+Click or Right+Click on the app to display the Finder's contextual menu. Then, choose Open. That's right. It's that simple.
Working around GateKeeper's security setting to launch an unsigned app.
An alert is still displayed, warning you that the app is from an unknown source. But, this time, you have the option to continue opening it. Choose to do so, and the app is whitelisted. Now you can open it anytime by simply double-clicking on it, just like any other app on your Mac. And, GateKeeper goes back to protecting your Mac from other potentially risky apps.
GateKeeper warns you that the app is not signed, but still gives you an option to open it.