macOS Big Sur introduces a host of new features, with significant enhancements to the Safari web browser, including expanded support for web extensions, which traditionally have been limited compared to other browsers like Chrome and Firefox. The update allows developers to create Safari web extensions using HTML, CSS, and JavaScript, facilitated by the new Xcode 12, which enables the building of Universal apps that support Macs with Apple Silicon without additional code changes. Developers must use Xcode to package and test Safari extensions, and membership in the Apple Developer Program is required to distribute them via the App Store. Xcode offers several features to streamline the development process, such as a command line tool for executing tasks directly from the terminal, converting existing browser extensions to Safari extensions, and creating cross-platform web extensions. The user-friendly interface of Xcode supports all devices and integrates Swift for an interactive preview of the user interface.