Judge Richard Posner was the perfect pick for mediator of the Microsoft antitrust case, observers said. "It would be hard to think of a better guy to appoint as mediator," Silicon Valley antitrust expert and attorney Richard Gray said. He cited Posner's "towering intellect" and thorough knowledge of antitrust law. Posner's credentials are substantial: Groundbreaking legal thinker, Chief Judge of the US Court of Appeals for the Seventh Circuit, dark horse Supreme Court candidate, and prolific author and one-time law professor at the prestigious University of Chicago law school, where he still lectures. "Judge Richard Posner is the single greatest antitrust scholar and judge of this generation," said Daniel Fischel, dean of Chicago's law school, in a statement. "There could be no better appointment." Fischel's statement noted that Posner (pronounced POSE-ner) pioneered the Chicago school of antitrust analysis, which centres on how laws affect consumers, "the central question in (the Microsoft) litigation." Posner's writings, such as his influential book "Economic Analysis of Law," have revolutionised antitrust law in the last three decades. Posner also co-founded Lexecon, an antitrust consulting firm, which he severed ties with after President Reagan appointed him to the federal bench in 1981. Both Microsoft and the Department of Justice should be pleased by Posner's appointment, observers said. "He's a very serious mediator and somebody that both parties would feel is a fair middleman in the picture, because he's somebody who can truly understand the economic arguments," said Charles Lipson, director of the program on International Politics, Economics and Security at the University of Chicago. Lipson, who said he has attended a number of Posner's workshops, noted that the Judge "is a polymath. He's one of the widest-read people I know." Lipson marvelled at Posner's ability to serve as a federal judge, write prolifically and still teach law. "I don't know when he gets to sleep." One attorney who recently left the Department of Justice said that Posner's credentials means neither side can quibble with his decisions. Indeed, Richard Schmalensee, the MIT economist who testified for Microsoft in the trial, at one point cited Posner's work during his testimony. But though Posner is considered a conservative, he's also written opinions in favour of partial-birth abortions and school desegregation. The liberal American Prospect, in an article assessing potential conservative candidates for the Supreme Court, called Posner "By far the most learned and capable conservative jurist," and noted that "Posner has written volumes of brilliant, quirky, wide-ranging commentary that succeeds at some point in upsetting just about everyone." What do you think? Tell the Mailroom . And read what others have said. Take me to the DoJ/Microsoft special .