The upcoming release of Windows 8 will include a version that expands Microsoft’s operating system to tablets that use the ARM architecture common in mobile devices. It’s part of Microsoft’s attempt to compete against the iPad.

But Firefox maker Mozilla contends that it will also give Internet Explorer an unfair edge over rival web browsers.

In Windows RT, the name of the version of Windows 8 for ARM devices, Firefox will be able to offer a Metro app, using the new tile-based design and development model that Microsoft is  introducing wit the new operating system. “However, Windows on ARM prohibits any browser except for Internet Explorer from running in the privileged ‘Windows Classic’ environment,” writes Harvey Anderson, Mozilla general counsel in a blog post.

He continues, “In practice, this means that only Internet Explorer will be able to perform many of the advanced computing functions vital to modern browsers in terms of speed, stability, and security to which users have grown accustomed. Given that IE can run in Windows on ARM, there is no technical reason to conclude other browsers can’t do the same.”

The situation will be different for Windows 8 on traditional x86 machines, with an approach that gives Metro-style browsers the ability to bridge the old and new environments. PCWorld has a good explanation of the technical aspects situation.

Anderson says the situation has antitrust implications. Microsoft has agreed to abide by a set of principles to maintain a level playing field on Windows for competitors despite the expiration of its consent decree with the U.S. Justice Department.

However, while the company dominates the traditional PC market, it’s starting from scratch on ARM devices, and it’s not clear how regulators would define the relevant market, which is one of the key issues in antitrust cases.

Microsoft hasn’t yet commented publicly on the Firefox post, but we’ve asked the company for a statement, and we’ll update this post if we get one.

Like what you're reading? Subscribe to GeekWire's free newsletters to catch every headline


  • Guest

    Has Firefox [sic] objected to most smartphones bundling a superior Webkit browser as a core component?

    Honestly, if the Mozilla Foundation spent half its whining time writing a decent web browser and stopped riding Netscape’s coattails from 1994, they’d have 90% market share again. They’ve already lost the mainstream crowd to IE and the hacker crowd to Webkit. Why would a person decide to use Firefox?

  • Odog4ever


    Apple won’t let you have a native 3rd party browser not running the Safari/Webkit engine?
    What browsers can you install on Chrome OS?
    What browsers can you install on Firefox’s own Boot-to-Gecko?

    Seems like this is an industry wide practice…

  • Guest

    Given the focus for WRT, I can understand MS’s position. Of course they could have helped themselves by calling the product something other than Windows_x. Metro, for example, would probably have been a better choice. Not only would that better clarify for consumers that this is a different product than legacy Windows, albeit that it shares code, it would likely also help the product’s chances in the marketplace. While MS’s SLT continues to operate in denial, the fact is that “Windows” as a brand now carries a lot of negative baggage which W7, good as it is, has only been able to marginally reduce.

  • Guest

    Did FF similarly complain when Apple didn’t allow it on iPad? Also, isn’t FF now almost totally dependent on Google for its financial solvency? If so, that should be pointed out for the record.

  • Guest

    Almost as sad as Mozilla’s whining, is Google supporting their complaint and talking about “open competition” while blocking WP from accessing Youtube metadata.

  • Discordia


    Oh, wait – they’re serious????

    M$FT may be a lot of things, but a tablet- (or even phone-) monopoly, they are definitely not.

    Good luck trying to sell that one to the DOJ.

  • Aaron Evans

    I keep Firefox 3 around for testing purposes, but they were done as soon as they released FF4/5/6/7/8/9/10/11.  I will not be supporting Windows 8 for a long time, if ever.

    • Guest

      Firefox 12 now. Only seven more releases until they’re as advanced as Chrome is!

  • Guest


    Apple doesn’t allow Firefox on iOS, Mozilla’s reaction:
    MS gives Firefox and others full access to Metro on WRT but not W32, Mozilla: antitrust! antitrust!

    This is getting old.

Job Listings on GeekWork

Find more jobs on GeekWork. Employers, post a job here.