Conventional wisdom has it that Judge Thomas Penfield Jackson has already made his mind up on the Microsoft trial: The software colossus is guilty of violating antitrust laws. But you wouldn't have known it during testimony on Dec. 10. Jackson asked a pointed question of government witness James Gosling, the chief scientist at Sun Microsystems, that rattled a table full of Justice Dept. lawyers by calling into question their argument that Microsoft has illegally tried to subvert Sun's Java technology.

The stunner came just as lead government attorney David Boies ended his redirect questioning. Jackson, whose eyes glazed over at the technical repartee during the past few days, suddenly perked up and put Gosling on the spot. "Mr. Burt [a Microsoft attorney] has presented evidence that Microsoft grasped the importance of Java and ran with it and just made a better product," he said. "What's your response?"

Gosling's response was none too convincing. He acknowledged that Microsoft's Java "virtual machine," the software that allows Java-based programs to run on a computer, is better in some ways than those produced by other licensees and that Microsoft has moved faster than Sun to improve its technology. "But their version of better is tied to the Windows platform," he said.

SHADOW OF A DOUBT. Alarmed at the turn of events, Boies leaped back up to buttress his line of attack with some additional questions -- but the damage had been done. During a press conference after the court session ended, he conceded that Jackson's question "reflects he was impressed with a number of points Microsoft made." But Boies said he also believes the judge was impressed with Gosling's answer. "Yes, Microsoft was trying to compete on the merits and come up with better software, but it also had its thumb on the scale," he said.

The government charges that Microsoft illegally altered its Java software in ways that confounded Sun's attempts to offer a technology that developers can use to write programs that can run on any computer -- which is a threat to Microsoft's Windows monopoly. It says Microsoft set out to torpedo Netscape Communications' Navigator browser because it was the primary distribution channel for Sun-approved versions of Java.

But four days of testimony by Gosling didn't seem to make that case beyond a doubt. Microsoft showed that software reviewers judge its Java virtual machine to be better than any others -- including Sun's -- at running applications written in the Java programming language. Microsoft presented evidence that the Java virtual machine shipped with Netscape's products was inferior to its product -- and didn't comply with Sun's compatibility rules, either. And it argued that it should not be punished for urging developers to use Java to write programs specificially for Windows.

Microsoft's attorneys could hardly conceal their jubilation during their post-testimony PR session. Lead attorney John Warden said he wouldn't comment on Jackson's question to Gosling, but he did say Gosling's complaints just don't ring true. "Microsoft produces the fastest and best Java technology," Warden said. "We're providing choice, and that's what competition is all about."

CREAM PIES. In spite of Microsoft's apparent gains on Thursday, Gosling was able to keep his sense of humor. When asked during the press conference what remedies the government should seek, he quipped: "Maybe they should be issuing cream pies" to all the developers with airplane tickets to Redmond -- where Microsoft is located.

Justice is no doubt hoping for a stiffer punishment than that. Its next chance to put Microsoft back on the defensive comes on Monday, Dec. 14, when Edward Felten, a computer science professor at Princeton University, is scheduled to take the stand. He has been called to show how Microsoft has welded its browsing technology to Windows 98 in ways the government says are unfair.

By Steve Hamm in Washington