The Mac App Store is the safest place for users to get software for their Mac, but we also want to protect users when they get applications from other places. Gatekeeper is a new feature in OS X Mountain Lion that helps protect users from downloading and installing malicious software.
Signing your applications, plug-ins, and installer packages with a Developer ID certificate lets Gatekeeper verify that they are not known malware and have not been tampered with.
Mac Developer Program members can sign applications with their Developer ID now to get ready for Gatekeeper. If you’re not already a member, join the Mac Developer Program today.