Earlier quoted context omitted.
Read what Gruber writes about that Gatekeep feature: My favorite Mountain Lion feature, though, is one that hardly even has a visible interface. Apple is calling it “Gatekeeper”. It’s a system whereby developers can sign up for free-of-charge Apple developer IDs which they can then use to cryptographically sign their applications. If an app is found to be malware, Apple can revoke that developer’s certificate, render…
Read what Gruber writes about that Gatekeep feature: Read what the world's biggest Mac-shill has to say to defend the world's least open company and biggest patent-troll? Thanks, but no thanks. I'll go for something open and free, and you wont get anything like that out of Cupertino.
You do know the core OS, Darwin[0], is open source? See also http://opensource.apple.com/ You may have even heard of a little rendering engine named WebKit that Apple helped create.