The claim is supported by extensive court evidence and government filings from United States v. Microsoft Corporation (2000-2001). A declaration by David S. Sibley for the U.S. Department of Justice [2] explicitly states: 'Microsoft engaged in specific anticompetitive actions intended to displace the Netscape browser with its own Web browser, Internet Explorer (IE). In particular, the commingling and contractual browser restrictions that Microsoft insisted upon in its agreements with OEMs, IAPs, ICPs, and Independent Software Vendors (ISVs) impeded the growth of the Netscape Web browser.' The declaration further documents that 'Microsoft erected artificial entry barriers to slow or halt the natural tendency of the marketplace to provide certain alternative technologies (known as "middleware") that have the potential to erode Microsoft's operating system monopoly.' Judge Thomas Penfield Jackson, ruling in the District Court, found that Microsoft had 'placed an oppressive thumb on the scale of competitive fortune' [1]. The court found Microsoft guilty of monopolistic behavior under the Sherman Antitrust Act, specifically citing the tying of its web browser to the operating system and restrictions placed on OEMs' ability to uninstall Internet Explorer or promote competing browsers like Netscape [4]. Microsoft's market dominance through these practices was quantifiable: by 2002, Microsoft controlled more than 90% of the browser market [1]. The remedies imposed (after the breakup order was overturned on appeal) included provisions requiring API disclosure and licensing of communication protocols, directly addressing the OEM restriction practices [2].