A quick look at a “About this Mac” window in today’s keynote showed the version number of the copy of macOS running on the Apple Silicon development hardware was 11.0, but Apple is also using the new name on the Developer website:
macOS 11 introduces many user interface changes that update the appearance of apps and make them more approachable to people transitioning from iPad apps. macOS 11 also adds support for familiar iOS features — such as SF Symbols and text styles — that enhance the user experience and can streamline the app design process.
When you build your app for macOS 11, you’ll find that most of the updates are automatic when you use system-defined elements with SwiftUI or Auto Layout; if your app is highly customized, you may have additional work to do. As you think about updating your app for macOS 11, review the following changes to help you plan your approach.