Apple has Safari Technology Preview 10. The experimental browser, which first debuted on March 30, offers users the ability to test features that may eventually be included in future publicly released versions of the Safari web browser.
Safari Technology Preview 10 includes bug fixes and updates for JavaScript, web APIs, Apple Pay, Web Inspector, MathML, rendering, accessibility, and security. Safari Technology Preview supports Apple Pay in the web browser, but you can’t really do much with it at the moment, until websites begin supporting it following macOS Sierra’s release.
Users can either download the update from the Safari Technology Preview website, or if they already have the browser installed, they can download it via the Mac App Store.
While the preview is intended for use by developers and advanced users, to provide Apple with feedback on the development of the Safari browser, it can be run side-by-side with the release version of Safari. The app doesn’t require a developer account to download and install. For more information, visit the Safari Technology Preview website.