For now. Macs used to allow installs of apps from anyone. Gatekeeper is currently set to only permit installs from the app store and developers who have paid

For now. Macs used to allow installs of apps from anyone. Gatekeeper is currently set to only permit installs from the app store and developers who have paid the yearly Apple tax by default now. ( http://support.apple.com/kb/ht5290 http://support.apple.com/kb/ht5290 ) In the next release or two, expect the Gatekeeper setting to be switched to app store only by default. Yes, you'll still be able to change it, but don't expect most users to.