Accusing Microsoft of following an approach which "may have antitrust implications," Mozilla's general counsel Harvey Anderson and Firefox director Asa Dotzler said - in their late-Wednesday blog posts - that Microsoft was withholding APIs required for building a competitive browser for Windows RT.

The accusations which Anderson and Dotzler have leveled against Microsoft are chiefly rooted in the software giant's decision to refuse other browser makers - including Mozilla - access to APIs (application programming interfaces) which are central to the running of a browser on a traditional Windows RT desktop.

According to the blog post by Anderson, Microsoft's decision to permit only Internet Explorer 10 (IE10) in one mode of Windows RT is a clear indication of "an unwelcome return to the digital dark ages where users and developers didn't have browser choices."

Meanwhile, in a more direct attack on Microsoft's allegedly competition-thwarting behavior, Dotlzer said, in his blog post, that the bigwig software company was trying to keep off competing browsers, particularly with regard to Windows equipped with ARM chips.

Even though Dotzler stopped short of elaborating on how Microsoft was exactly trying to limit access to rival browsers, he did mention that, on ARM chips, unique APIs which are absolutely essential for building a modern browser are accessible only by IE, while the other browsers are denied access to them; thus implying that Microsoft is hindering other browsers in their competition with IE, both in terms of "features" and "performance."