Microsoft has been hit with a public complaint of anti-competitive behaviour over its forthcoming Windows 8 operating system, marking a possible return to the regulatory and legal wrangles that have beset it over the past decade.
Mozilla, the organization behind the Firefox browser, accused the software giant of unfairly limiting Web access on some versions of Windows 8 to its own in-house browser, IE. The claim echoes complaints made to Europe over earlier moves by Microsoft to promote its own browser over rivals, which eventually led the software company to agree a settlement that gave PC users greater choice.
Harvey Anderson, Mozilla's general counsel, said that the non-profit organization had yet to lodge a formal complaint with regulators over the issue, though he said Mozilla would act "if we have to. Rushing off for regulatory relief is not our first priority."
At the heart of the Mozilla protest is Microsoft's attempt to use Windows 8 to fight back against Apple in the tablet market, a move that has turned the expected release of the software later this year in to the company's most important new operating system since Windows 95.
To compete with tablets and other mobile devices anticipated in the future, Microsoft is set for the first time to release a version of Windows that runs on low-power ARM processors, rather than the Intel-compatible chips it has always worked with in the past.
The ARM-based machines have been designed so far only to work with the IE browser, excluding independent software like Firefox, Google's Chrome and Apple's Safari. However, those browsers will continue to work with traditional Intel-compatible PCs, for which Microsoft is producing a separate version of Windows 8.
"If users and developers don't have a choice, it will restrict competition" on the new class of Windows machines, Mr. Anderson said. Restrictions on Microsoft's business practices in the U.S., which resulted from an antitrust consent decree a decade ago, have largely expired, though the company's conduct is still more tightly governed under a European regulatory settlement, making that a possible avenue for action.
Complicating the picture is the fact that Apple, which dominates the new tablet market with the iPad, also blocks third-party browsers, forcing customers to use its Safari software.
Microsoft is likely to claim that it is simply adopting the same practices for the new, more "closed" mobile devices as its competitors, and that it is starting out with no market share at all in the new market, Mr. Anderson conceded.
However, he said that previous regulatory analyses of the Windows monopoly had never been based on the particular chips that the software runs on, and that Microsoft would also be able to use its strength in the traditional PC market to gain market share on new touchscreen, ARM-based devices.