Apple launched this evening not only iOS 10GM, but also macOS Sierra GM, together with watchOS 3 GM and tvOS 10 GM, all its products benefiting from the latest versions of the operating systems. We are of course talking about the final versions of Apple's operating systems that are offered in advance to developers for testing to discover bugs.
The final version of macOS Sierra is to be offered by Apple on September 20 for free to all Mac owners, but if you install the GM version, you have everything from now on. Those from Apple will release the updates during the evening, so you know when to expect to be able to do the installation.
