Anyone could develop software for the Macintosh prior to the release of OS X. There were third-party tools to do so. You could extend the system software. Yo

Anyone could develop software for the Macintosh prior to the release of OS X. There were third-party tools to do so. You could extend the system software. You could distribute your software as you pleased. Depending upon how you look at it, it was actually more open than OS X development since modern releases of OS X lock certain things down in the name of security. Both are a far cry from iOS development.