I'm trying to minimize the cost of code-signing certificates necessary to develop a program for Mac OS X and Windows. As far as I can tell, I can't use a 3rd party certificate to sign my OS X program and have it get past GateKeeper, as indicated here.
Can I go the other way and use an Apple Developer certificate to sign the Windows version of my program?
Also related: Non-Apple Issued Code Signing Certificate: Can it Work with Mac OS 10.8 Gatekeeper?
Had the same idea some time ago. But I don't think it's possible, because the Apple Developer Certificate is verified (signed) by Apple and I don't think that the Apple Root Certificate is installed on average Windows machines.