A respected computer users group has begun lobbying the U.S. Congress to ignore arguments against open-source software made by Unix vendor The SCO Group. In an interesting twist, both a Microsoft research engineer and a computer executive fired by his company for criticizing Microsoft have contributed to the effort.A respected computer users group has begun lobbying the U.S. Congress to ignore arguments against open-source software made by Unix vendor The SCO Group. In an interesting twist, both a Microsoft\u00a0research engineer and a computer executive fired by his company for criticizing Microsoft have contributed to the effort.On Friday, the Usenix Association, a 6,000-member nonprofit association of technical computer users based in Berkeley, Calif., published an open letter refuting many of the arguments that SCO had been making to Congress, including that Linux and open source software ran contrary to U.S. interests.Usenix plans to send the letter to members of Congress and to a number of committees, caucuses and leadership organizations in Washington, D.C., according to association spokeswoman Wendy Grubow.The Usenix statement was written after a letter that SCO had been circulating to Congress last month was published on the Web site of an open source lobbying organization called the Open Source and Industry Alliance, said Marshall Kirk McKusick, the president of Usenix's board of directors.SCO has been involved in a highly publicized dispute with the open source software community over SCO's claims that the Linux operating system illegally contains code that belongs to the Unix vendor. These claims are at the heart of ongoing lawsuits filed in the last year between SCO and IBM, Red Hat, and Novell.SCO's letter, which was sent to the 535 members of the U.S. Congress, called Linux and open source software a threat to the security and economy of the U.S. "Open Source software -- available widely through the Internet -- has the potential to provide our nation's enemies or potential enemies with computing capabilities that are restricted by U.S. law," the letter said. It said Linux's GPL (GNU General Public License) software license was "in direct contradiction to U.S. copyright law."Usenix's response to SCO takes the Lindon, Utah, company to task on both points. "SCO's own programmers themselves use open source computer software tools, so it is difficult to explain SCO's position except by noting its hypocrisy," the Usenix letter states.The letter also argues that the software licenses have no effect on U.S. security. "Intellectual property law is not the right place to impose restrictions on the use of computer programs abroad," the letter states. "That's what our export control laws do."The Usenix board had discussed the idea of taking on SCO in the past, but had not taken action before SCO's January letter, said McKusick. "The thing that got our ire going in the letter to Congress was this notion that open source is dangerous to our economy and dangerous to IP\u00a0rights, and that somehow Congress ought to prevent this," he said.The Usenix membership would suffer if Congress moved to restrict the use of open source software, said McKusick, himself a key contributor to the open-source Berkeley Software Distribution operating system. "We want our constituency to have as much choice as possible. By somehow implying that open source software is bad and should be stomped on, that narrows the set of choices our members have to draw on," he said.The issue prompted a response even from Usenix members affiliated with Microsoft, which has publicly opposed the open-source methodology. The first draft of the association's letter was written by board member Michael Jones, who is also a researcher at Microsoft's Systems and Networking Research Group. A subsequent draft was written by Dan Geer, McKusick said. Geer is a former CTO\u00a0with Cambridge, Mass.-based @Stake\u00a0who was fired from that company after participating in a study that suggested that Microsoft's monopoly was bad for computer security."The Usenix Board believes that people should be free to enter whatever contracts they chose, including all forms of software licenses," Jones wrote in an e-mail interview. "I can't speak for Microsoft, but I believe you'll find press releases on our Web site saying that Microsoft believes that customers do and will chose to purchase our software exactly when it is the best value proposition to meet their needs."SCO Spokesman Blake Stowell had no comment on the matter other than to say that SCO stands by the claims it made in its letter to Congress.The Usenix letter can be found\u00a0here.