From the Macworld article of the same day it was pretty clear that you needed to be part of the Apple developer program: http://www.macworld.com/article/116540

From the Macworld article of the same day it was pretty clear that you needed to be part of the Apple developer program: http://www.macworld.com/article/1165408/mountain_lion_hands_on_with_gatekeeper.html http://www.macworld.com/article/1165408/mountain_lion_hands_... The Ars Technica article also is pretty clear: http://arstechnica.com/apple/2012/02/developers-gatekeeper-a-concern-but-still-gives-power-users-control/ http://arstechnica.com/apple/2012/02/developers-gatekeeper-a... If there is confusion it may have been from reading more into what Gruber wrote than was actually there. The Gatekeeper certificates are free to registered developers, but I don't Apple ever suggested that you didn't have to be part of the Apple Developer Program.