One of the most important ways that Microsoft wants to make the new Chromium-based Edge different from the current EdgeHTML-based Edge is in its support for other platforms. The original Edge was, for no good reason, tied to Windows 10, meaning that Web developers on platforms such as Windows 7 or macOS had no way of testing how their pages looked, short of firing up a Windows 10 virtual machine.

The new browser is, by contrast, a cross-platform affair. The first preview builds were published for Windows 10, with versions for Windows 7, 8, and 8.1 promised soon; today, these are joined by builds for macOS.

The macOS version resembles the Windows 10 builds that we've seen so far, but it isn't identical. Microsoft wants to be a good citizen on macOS by producing not just an application that fits the platform's standards—using the right fonts, icons, spacing, and so on—but which also adapts to Apple's unique hardware. To that end, the company is working on support for the Touch Bar found on some of Apple's portable systems, using it for media control, tab switching, or access to bookmarks. Microsoft will also work to ensure that Edge's support as a Progressive Web App host properly adopts macOS behaviors with regard to interaction with the Dock, app switcher, and Spotlight.

This stands in contrast to the Windows 10 version, where the old Edge makes much more use of modern Windows' Fluent Design than the new one. Indeed, Edge was one of the most eager adopters of Fluent Design. As part of adopting the Chromium user interface, much of this work has been lost.

The build requires macOS 10.12 and above, and it is initially available in the Canary channel, updated daily or thereabouts. In the coming weeks, a dev channel build will be published and updated weekly, followed by a beta channel build, which will get updated every six weeks.