Caldera v. Microsoft

Microsoft has been involved in numerous high-profile legal matters that involved litigation over the history of the company, including cases against the United States, the European Union, and competitors.

In its 2008 annual report, Microsoft stated:

In the 1990s, Microsoft adopted exclusionary licensing under which PC manufacturers were required to pay for an MS-DOS license even when the system shipped with an alternative operating system. Critics attest that it also used predatory tactics to price its competitors out of the market and that Microsoft erected technical barriers to make it appear that competing products did not work on its operating system. In a consent decree filed on July 15, 1994, Microsoft agreed to a deal under which, among other things, the company would not make the sale of its operating systems conditional on the purchase of any other Microsoft product. On February 14, 1995 Judge Stanley Sporkin issued a 45-page opinion that the consent decree was not in the public interest. Later that spring, a three-judge federal appeals panel removed Sporkin and reassigned the consent decree. Judge Thomas Penfield Jackson entered the decree on August 21, 1995, three days before the launch of Windows 95.

A Microsoft purchase of Intuit was scuttled in 1994 due to antitrust concerns that Microsoft would be purchasing a major competitor.

After bundling the Internet Explorer web browser into its Windows operating system in the late 1990s (without requiring a separate purchase) and acquiring a dominant share in the web browser market, the antitrust case United States v. Microsoft was brought against the company. In a series of rulings by judge Thomas Penfield Jackson, the company was found to have violated its earlier consent decree and abused its monopoly in the desktop operating systems market. The "findings of fact" during the antitrust case established that Microsoft has a monopoly in the PC desktop operating systems market:

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