News

Microsoft Now Signaling a Clean Break Between Spartan and IE Browsers in Windows 10

• By Kurt Mackie
• 03/24/2015

Microsoft announced a switch today from its previously outlined Windows 10 browser development strategy.

Windows 10, currently at the preview stage, is being built with two browsers, namely Internet Explorer 11 and a new browser code-named "Spartan." These two browsers were both expected to contain two different Trident rendering engines -- one that's designed to support the so-called "modern Web" (called "EdgeHTML") and another engine (MSHTML) that would ensure maximum compatibility with past "legacy" Microsoft browser technologies.

Today, Microsoft indicated that, based on feedback from Windows 10 testers, the engineering team now plans to deliver the Spartan browser without the legacy Trident engine included. IE 11 will still be available when Windows 10 gets released, but it's mostly for organizations with intranet sites or Web apps that need to maintain older Microsoft browser technologies for compatibility reasons. In addition, Microsoft plans to omit the new EdgeHTML rendering engine from its next IE 11 browser, deviating from previously stated plans.

Here's how Microsoft's announcement described this change in plans:

Today we're announcing that on Windows 10, Project Spartan will host our new engine exclusively. Internet Explorer 11 will remain fundamentally unchanged from Windows 8.1, continuing to host the legacy engine exclusively.

The Spartan browser will be the default browser in Windows 10. Contrary to many news reports, Microsoft isn't killing off IE. Instead, it has forked the development of the Trident engine with EdgeHTML in Spartan and jettisoned a lot of old code. IE will be maintained for legacy support purposes using the older Trident engine and code, but clearly Spartan will be Microsoft's path forward. If an organization needs to use IE, they can configure it to be the default browser using Group Policy settings.

Part of Microsoft's plan with the Spartan browser is to shift developer expectations. Many developers today associate the IE name with quirks they had to accommodate when developing their Web sites and apps in the past. Consequently, Microsoft is starting anew with Spartan, according to explanations by Jacob Rossi, a senior engineer on the Microsoft Web platform team. Spartan will be a continuously updated browser built for Windows 10, and possibly for Windows 7 (depending on demand), according to Microsoft. It will have the capability to run extensions, if wanted.

Spartan also will add some new user experiences, such as "annotation, distraction-free reading, and Cortana integration," according to Microsoft's announcement today. Microsoft is also claiming that its tests have shown that Spartan has been "highly compatible with the modern Web, which means the legacy engine [MSHTML] isn't needed for compatibility."

Microsoft hasn't released the Spartan browser yet with its preview builds of Windows 10, but it's expected to arrive "starting in the next flight to [Windows] Insiders," per Microsoft's announcement. At that time, Microsoft also plans to remove the EdgeHTML rendering engine from IE 11. Microsoft has been releasing its new builds of Windows 10 on a monthly basis.

While the Spartan browser isn't yet available today, it's possible to change Windows 10 preview settings to test the EdgeHTML rendering engine. Alternatively, EdgeHTML can be tested by using Microsoft's RemoteIE browser as a service option.

In other Microsoft browser news, the company noted yesterday that it has opened up Spartan development to Adobe's web platform team. Adobe has contributed a new CSS gradient feature in the March Windows 10 build that generates color shading from a midpoint value, as well as a new extended blend-mode feature.

Apparently, Adobe was restricted in its ability to contribute to the Trident engine in past years, even though it had contributed code to other browser engines, such as WebKit, Blink and Gecko. Trident is proprietary Microsoft technology, and it likely still is proprietary with the forked version of Trident that will be used with the Spartan browser. Somehow, though, third-party developers have better access to that code, Microsoft seems to be suggesting.