Microsoft is accused by the US Department of Justice (DOJ) and 19 US states of illegally using its dominance in PC desktop operating systems to try to quash competition in other areas, such as the market for Web browsers.
In effect, Microsoft document is a rebuttal of the government's rebuttal of the software company's legal defense.
Once again, as the firm has done in previous filings in the case, Microsoft defended itself using firm and certain terms.
"By lambasting Microsoft, plaintiffs apparently hope to draw attention away from the flaws in their case," the Microsoft rebuttal said. "Time and again, plaintiffs' only support for bold pronouncements about applicable legal principles is a citation to their own proposed conclusions of law -- which themselves contain little in the way of legal authority."
The US government has argued that Microsoft violated antitrust laws and that the company in its conclusions of law filing a week ago ignored the substantive issues of the case, instead addressing "strawmen," and taking "a series of potshots," while also misstating legal standards to evade the relevant points in the dispute.
Microsoft rebuttal attempts to deconstruct the government's earlier filing with numerous examples of case law and other pointed criticisms of the way the DOJ has backed up its case. The software maker says the DOJ failed to provide specifics for its "strawmen" assertion and sought to apply out-of-context passages from decisions involving different market circumstances.
After Jackson ruled last November in his findings of fact that Microsoft is a monopoly, each side was allowed to respond with conclusions of law, which set forth how the software maker and the US government believe that antitrust law should be applied to the judge's findings of fact. Each side also was granted the opportunity to file rebuttal briefs arguing points made in the other's conclusions of law.
Microsoft consistently has defended its actions, contending that it is not a monopoly and that it has not misused its market position.
The software vendor's brief says the government's tying claim involving the integration of Microsoft's Internet Explorer Web browser and Windows operating system fails because the Windows 98 OS is a single, integrated product. Microsoft claims it is not forcing any customers to purchase a second distinct product, and the alleged tie does not foreclose a substantial amount of sales of the allegedly tied product.
The company further argued in the brief that Microsoft's license agreements with PC manufacturers do not constitute an unlawful restraint of trade, and it says the DOJ's attempted monopoly claim flies directly in the face of settled cases.
Microsoft has said all along that it has not engaged in illegal anticompetitive behavior by, for example, forcing other vendors to sign exclusionary deals that cut rival companies, particularly Netscape Communications (now part of America Online), out of the Internet software market.