A federal judge in a Baltimore courtroom Tuesday peppered lawyers from both Microsoft and Sun with probing questions as the two sides presented opening arguments in a pretrial hearing in Sun's private antitrust case against the software giant.U.S. District Court Judge Frederick Motz questioned whether the preliminary injunction requested by Sun - forcing Microsoft to carry Sun's Java Virtual Machine (JVM) on every copy of Windows and Internet Explorer - would give Sun an unfair competitive advantage.During opening arguments in the hearing, called to determine the merits of Sun's request, Motz asked Sun lawyer Rusty Day if the injunction would not only give the Java programming suite an advantage over Microsoft, but also one over other competitors."I came into this asking ... if you've got the better product why do you need the remedy?" Motz asked. He noted that U.S. District Court Judge Colleen Kollar-Kotelly had "vehemently" denied a similar request in her antitrust settlement ruling for the U.S. government's case on Nov. 1.Day answered that without the order, Microsoft would use its operating system monopoly to promote its .Net development platform and destroy Sun's Java. "We are in the path of irreparable harm going forward if you do nothing," Day said.The remedy Sun is requesting would require Java to be compatible with the Java Community Process, which is controlled by several other companies, Day said.Sun, however, could achieve a distribution of Java similar to that of Microsoft's .Net by spending a relatively small amount of money with OEMs, said Microsoft lawyer David Tulchin, who made a similar point during his opening argument.Tulchin cited a Sun internal document saying that Java could reach the majority of PCs if the company spent $4 million a year with OEMs, a small amount of money for a company that had about $12.5 billion in sales in its last fiscal year.Sun is also confusing the operating system market, in which Microsoft has a legal monopoly, with the Web services market, in which Sun already has a competitive advantage, he said."Only with PCs do they want the court to intervene," Tulchin said. "They're not looking for distribution parity in wireless devices; if so, Microsoft would need help."Java already has a huge advantage over the competition in other devices besides PCs, he said, nothing that .Net, which is Microsoft's answer to Sun's Java programming platform, is not yet shipping on most PCs. He pointed to Sun internal documents projecting Java being used on more than 700 million wireless devices by 2004, more than double the estimated number of PCs currently being used."They didn't tell you that they already have and expect to have in the future dominance in handhelds, cell phones and application server devices," Tulchin said.Kollar-Kotelly rejected a similar remedy in the federal antitrust case because she said it was anticompetitive, Tulchin said. "Before .Net was introduced Java was alone in the (Web services) market. It had the whole market to itself."But Motz also questioned Tulchin about Microsoft's past actions, at one point comparing the Java market to the Netscape-Internet Explorer wars.In response to a question from Motz about how Sun's proposed solution would hurt Microsoft, Tulchin argued the remedy could damage Microsoft in several ways, including Sun's Java potentially not working right with Windows.In afternoon testimony, Rich Green, Sun's vice president of the Java platform, disputed Tulchin's contention that Microsoft could be forced to provide support for Sun's version of Java if Microsoft were made to distribute it. Green used the example of RealNetworks, which has its multimedia products distributed on Windows and provides the support for those products.Green's testimony, which lasted about five hours, was dominated by pie charts and predictions about what will happen if Microsoft distributes .Net but does not also distribute Java. Green suggested that Sun's attempts to level the market by other methods won't make up for Microsoft's huge operating system distribution advantage.Green said Sun is imploring OEMs to include the Sun-compatible Java on their computers. If Motz denies the Sun injunction, the impact on Java would be "significant," he added."I don't see a mode where it could be corrected going forward," he said.Tulchin and Green reacted testily to each other at times during cross examination. At one point they argued over the timing of when Green changed job titles at Sun. Tulchin questioned how Sun could prove it would be irreparably damaged if the injunction was denied, and he continued to hammer on his point that Sun and IT analysts were predicting growth for Sun on a variety of devices.Veteran software developer Rick Ross, president of Javalobby.org, testified, however, that developers expect .Net to be distributed to "the four corners of the earth" over the next couple of years, and said that if Java doesn't achieve the same level of distribution, developers will flock to .Net. "Developers have a strong incentive to go with the technology that's more widely distributed," Ross said. "Go with the market leader - it's the safe thing to do."The hearing continues Wednesday with Microsoft witnesses. Closing arguments are scheduled for Thursday.In its lawsuit, filed in March, Sun argued that Microsoft has attempted to fragment the Java platform by distributing its own Virtual Machine for Java, which is incompatible with Sun's Java development products. By doing so, Sun claims, Microsoft illegally held back Java as a cross-operating system development tool and reinforced its operating system monopoly.Sun argues that Microsoft continued its monopolistic actions when it began distributing Windows XP without any Java runtime in October 2001. When Web surfers using Windows XP encounter a Web site requiring a Java virtual machine for the first time, they see a notice saying they must download the Microsoft Virtual Machine for Java to see the page correctly."By forcing customers to engage in a time-consuming separate download, Microsoft not only is acting outside the scope of its limited copyright from Sun, it is purposely making it more difficult for customers to access the millions of web pages containing Java applets," Sun's lawyers write in the motion for preliminary injunction.Sun has maintained that it needs the court's intervention before Microsoft uses its operating system monopoly to dwarf Java's market share with Microsoft's new .Net development platform. Sun's lawyers suggest the remedies they want would be a minor inconvenience for Microsoft, compared to the potential damage to Sun's business if Microsoft is able to give .Net the same advantage over Java as it did with Internet Explorer over rival browser Netscape."By using the massive distribution channels afforded by its monopoly power, Microsoft will quickly be able to blanket PCs with a runtime that will compete with the Java platform, while simultaneously excluding the Java platform from its monopoly products," Sun says in the motion for preliminary injunction.The preliminary injunction, scheduled to last through Thursday, is one of a variety of remedies that Sun is seeking, including monetary damages and a permanent injunction that would require Microsoft to license its proprietary software interfaces to other companies and to "unbundle" products such as Internet Explorer and the IIS Web server.These remedies are similar to those sought by states that declined to sign on to a settlement between Microsoft and the U.S. Department of Justice. The states' remedies were largely denied by Kollar-Kotelly. Only two of the states, Massachusetts and West Virginia, have decided to appeal Kollar-Kotelly's decision.Microsoft also faces private lawsuits filed by Be, AOL Time Warner, which owns Netscape Communications, and Burst.com. These suits are being coordinated and presided over by Motz.