Apple has sent out an email to developers that are a member of Apple’s Mac Developer program, encouraging them to sign up for a Developer ID certificate. This  certificate will enable developers to offer applications outside of the Mac App Store that will install on Macs running Apple’s new Mountain Lion OS.

The new OS contains a feature called Gatekeeper which will eventually prevent any applications from being installed that are not signed with a Developer ID certificate.

The email encourages developers to sign up for their ID, saying that “As a member of the Mac Developer Program, you are immediately eligible to obtain and use Developer ID code signing certificates.”

71989 Apple prompts Mac developers to sign up for the Developer ID program

Get your applications ready for Gatekeeper today. It’s easy to get started with Developer ID using the automated certificate request tools in Xcode 4.3 or the Developer Certificate Utility.

Apple is billing Gatekeeper as a security feature for users of the Mac. At its core is the ability of users to control which apps are able to be installed onto their computer. Apple describes the controls this way:

For maximum security, you can install and run only apps from the Mac App Store. You can choose to install and run apps from the Mac App Store and apps that have a Developer ID. Or you can install all apps from anywhere, just as you can today. You can even temporarily override your setting by Control-clicking, and install any app at any time.

With Gatekeeper, Apple is defaulting casual Mac users to installing apps that are purchased through the Mac App Store and signed digitally via the Developer ID Program. This is a free certification that allows developers to sell apps right from their websites, but allows Apple the ability to disable or disallow those apps if they become an issue.

Essentially, there are three settings:

  • Install only stuff from the Mac App Store
  • Install stuff from the MAS and stuff from any site that has been signed by a Developer ID certificate
  • Install anything that you want

Gatekeeper may not be the solution to everything that ails the Mac App Store’s sandboxing and app restriction issues though. Developers are cautiously optimistic about the system, but some still point out that there are issues with Apple’s consumer-focused stance that may prevent their apps from being run on Mountain Lion at all, much less in the restrictive environment of the Mac App Store.

Regardless, Apple feels that the Developer ID program is the right way to offer an alternative to those developers feeling the bite of sandboxing restrictions. If you’re a developer interested in the program, you can get more information here.