Citing anonymous sources, Windows Central reports that Redmond is forging ahead with a plan to replace or retool the Edge browser in Windows 10 with a Chromium-powered replacement. The project is apparently codenamed "Anaheim," though there's no telling whether Microsoft's new browser will keep or ditch the Edge branding.
For the uninitiated, Chromium is the open-source web rendering engine that forms the basis of the ever-popular Google Chrome browser. It also underpins a handful of other browsers like Opera, Vivaldi, and even Steam's in-game web browser. Microsoft reportedly wants to fix Edge's unimpressive mindshare among users and developers by building a new browser on this popular, well-understood engine. Edge's current engine, EdgeHTML, is perfectly functional and a far sight better than Internet Explorer ever was. However, the browser's sparse feature set and lack of choice for extensions have largely relegated it to an also-ran.
Whatever the rationale behind this decision is, Anaheim will likely be compatible with the huge number of Chrome extensions out there. Moreover, using an engine that's common among the majority of browsers lets developers (and in turn, users) avoid inter-browser website compatibility issues. It's not all roses, however. As those old enough to remember the dark days of Internet Explorer hegemony will certainly recall, having a single rendering engine powering most of the known browser world means that "web standards" are whatever that engine decides to do. The fact that Chromium is an open-source project might somewhat assuage that fear.
As corroboration for that idea, Windows Central remarks that some Microsoft engineers have contributed code to the Chromium project in a bid to ease Chrome compatibility on ARM-based devices. The site thinks that Microsoft will add Anaheim to the Windows 10 Insider builds sometime in the first half of 2019, so we'll see whether Microsoft plans to shine up its browser with Chromium then.