Jackson asked numerous questions of both sides but was particularly tough on Microsoft. Government attorneys are clearly anticipating a strong verdict in their favor and plan to ask for severe sanctions.
"Remedies have to be drastic and far-reaching, because the findings of this conduct and predatory practices are so serious and significant," said Attorney General Richard Blumenthal of Connecticut, one of 19 states that brought the case against Microsoft.
Jackson may move quickly to issue a verdict. He has kept the trial on a fast track, limiting witnesses to speed the process. He released his more than 200-page findings of fact in November, less than two months after attorneys completed the first set of closing arguments.
Most telling about what the future may hold for Microsoft came when the judge compared the company's power over its operating system with the power John D. Rockefeller once had over oil, citing the famous 1911 Standard Oil case. The courts broke up Standard Oil, and government attorneys are considering the same remedy for Microsoft.
"Mr. Rockefeller had fee simple control over his oil," said Jackson, using a term that describes complete or unlimited control over property. "I don't see the distinction."
The judge's mention of the Standard Oil case underscored government arguments that antitrust laws developed to handle manufacturing also apply to so-called new-economy companies.
David Boies, the lead government attorney, offered a litany of antitrust violations against Microsoft, such as making inducements and threats to competitors. He assured Jackson that a verdict against Microsoft would pass the ultimate legal test.
"Try to imagine the U.S. Supreme Court ruling that these cases do not violate the antitrust laws," said Boies to the judge. "It's impossible to imagine."
But while John Warden, Microsoft's chief trial attorney, argued that Microsoft didn't violate any law, he also said the industry has rapidly changed since this case was brought and he warned that the wrong decision could endanger U.S economic prosperity.
"The success of this industry . . . is by common acknowledgment the engine that has driven the nation's unprecedented economic expansion," Warden said.
Jackson appeared particularly critical of the company's legal arguments that copyright law gives it control over how PC makers can use the Windows operating system, telling Warden he had problems with the arguments.
But Jackson questioned the government about its claim that Microsoft illegally tied its browser to its operating system. A 1998 appeals court ruling said Microsoft could legally integrate its browser with its operating system.
"The questions to Boies have their own troubling qualities for the government," said George Washington University law professor William Kovacic.
Neither side would offer any details about ongoing settlement talks, but sources close to the talks aren't optimistic that a settlement will be reached.