Best known as the judge who presided over the historic US antitrust trial against Microsoft, Thomas Penfield Jackson passed away on Saturday at the age of 76. After an illustrious career that involved several historic rulings, Judge Jackson in many ways was undone by his own improper behavior during the Microsoft trial—ironic, given the accusations against the then-software giant.

For those of us who closely follow the technology industry, Microsoft’s US antitrust trial was an unwelcome immersion into the world of antitrust law, one that lasted for several years and long outlived Jackson’s role. But it was Judge Jackson who set the fiery stage for a subsequent decade in which Microsoft’s market power was severely diminished not because of emerging rivals such as Apple and Google but because of internal reticence to trigger further antitrust inquiries.

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Ultimately, it was a clash of egos that doomed that Microsoft decade, with the firm’s co-founder and then-CEO Bill Gates on one stubborn side and Judge Jackson on the other. Jackson described Gates as “unethical” and compared him with both Napoleon and a drug kingpin. Gates, for his part, was probably correct in believing that the judge, a Luddite of sorts who chewed ice in court to help himself stay awake, had no business overseeing the industry he then dominated.

Sadly for Gates and Microsoft, it was Jackson—for a time, at least—who held the real power.

“Microsoft has demonstrated that it will use its prodigious market power and immense profits to harm any firm that insists on pursuing initiatives that could intensify competition against one of Microsoft's core products,” Judge Jackson wrote in his historic findings against the company. “Microsoft's past success in hurting such companies and stifling innovation deters investment in technologies and businesses that exhibit the potential to threaten Microsoft. The ultimate result is that some innovations that would truly benefit consumers never occur for the sole reason that they do not coincide with Microsoft's self-interest.”

Jackson’s findings led to a historic ruling in which Microsoft was found guilty of sweeping antitrust abuses and ordered split into two companies, one that would control Windows and one that would control Microsoft’s other software products. The findings and ruling were a wakeup call for Microsoft, and together finally triggered a behavioral change in the company that, if anything, was as radical in the other direction as was its belligerent behavior toward competitors, partners, and customers before that. It also triggered a series of similar antitrust investigations around the world, including a particularly damaging one in the even more punitive European Union (EU).

Jackson’s oversight of Microsoft was short-lived. Accused of bias against Microsoft—he excitedly discussed the case with reporters during the trial—his breakup order was rescinded by the Court of Appeals as the key finding against Microsoft—its artificial commingling of Windows with Internet Explorer (IE)—was reversed during appeal. And though Microsoft eventually orchestrated a weak settlement with the US government after the corporate-friendly Bush administration took office, it’s worth noting that the bulk of Jackson’s ruling—including eight findings of illegal monopoly business practices—were upheld through the appeal. Microsoft, as Judge Jackson had claimed, was guilty.

(Critics who had hoped for a more damaging outcome during Microsoft’s US antitrust trial were no doubt delighted when a more eager EU dragged the firm through its own antitrust courts for the next decade. Indeed, Microsoft this very year is still dealing with the ramifications of its antitrust abuses.)

Jackson’s behavior during the Microsoft trial has somewhat tarnished an otherwise illustrious carrier that touched on several historic events. Judge Jackson fined Michael Deaver, a former aide of President Ronald Reagan, for lying under oath in 1988. He oversaw the 1990 trial of Washington DC mayor Marion Barry, resulting in a guilty conviction for cocaine possession. And he ordered Oregon Senator Bob Packwood to surrender his personal diary to the Senate Ethics Committee in 1994, resulting in his resignation after it was revealed he had sexually harassed several staff and other people.

In 1997, Judge Jackson was involved in what was perhaps his most historic ruling, at least until the Microsoft trial: He ruled that the so-called line-item veto, in which a president could veto parts of a bill that were signed into law by Congress, was unconstitutional. Jackson’s ruling was upheld by the US Supreme Court. Ironically, the line-item veto was first requested by President Reagan, who nominated Jackson to the Washington federal court in 1982.

Jackson retired from that court in 2004. He died Saturday at his home in Compton, Maryland. Thomas Penfield Jackson was 76.

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