Even computer programmers can sometimes let their emotions get the better of them. "If I made a great product, and Microsoft offered me a lot of money, I would spit in their faces," says Brett Slatkin, a student at Columbia University in New York. His colleagues roll their eyes and accuse him of being stuck at the "hippy stage." But when talk turns to the serious business of programming, they are of one pragmatic mind.

One of the burning issues in computer circles is whether servers--the fastest-growing segment of the computer business--are going to run Microsoft software or an alternative, Linux, in the future. Microsoft's selling point has been its universe of tightly designed software that fits together like a puzzle, from the basic operating systems that make each computer run to software that controls networks to programs designed for specific tasks. But lately Microsoft has been placing more and more restrictions on how its software can be used. That bothers programmers, who crave the freedom to use the tools of their trade as they see fit.

Nobody, by contrast, owns Linux--it is "open source," as distinct from Microsoft's "closed source" software. This means programmers have more leeway in how they handle any problems that might come up, particularly those that pertain to security. For this reason, Linux is winning favor among young computer programmers about to enter the job market, whose preferences may prove decisive in the coming years.

Linux has recently been making headway in the marketplace. A few years ago, computer firms IBM, Dell, Compaq and others threw their support behind Linux, offering to accommodate it in their product lineups and support it for their customers. Companies were initially slow to make the leap, but in the past year some big firms, attracted in part by the prospect of saving money on license fees to Microsoft, have switched. Last October said it saved $17 million in one quarter, thanks in part to Linux. In February online broker E*Trade took the plunge and computer-maker Sun Microsystems bowed to marketplace pressure and said it would offer Linux on some of its computers. "I think everyone is going to use it," says Doctor Robinson, a programmer at Salomon Smith Barney, which adopted Linux a year and a half ago. Linux now accounts for 27 percent of server software worldwide, compared to Microsoft's 42 percent share, says research firm IDC.

In Germany, Linux is already becoming something of a movement. Whereas American corporations moved from mainframes to networks of personal-computer servers back in the 1980s, Europe lagged by a decade. By then, Linux had been developed into a robust competitor to Windows. European firms embraced Linux, and the Internet boom provided further impetus. Siemens, Deutsche Bank and Volkswagen have been using Linux for years--and by last year, says IDC, 40 percent of German corporations were doing so as well. Last week the Bundestag, Germany's Parliament, decided to switch its servers to Linux from Windows. "My wish would be to declare the entire Bundestag a Microsoft-free zone," said Jorg Tauss, a deputy for the Social Democrats. It would be irresponsible, he said, to entrust the work of Parliament to closed-source software.

Computer programmers are quick to point out that they don't impugn the quality of Microsoft's software. It has some advantages: it is generally more consistent in quality and easier to install on servers, especially for inexperienced programmers. Rather, the issue is more one of who controls the software. If a security loophole, say, is found in a corporate computer network that uses Linux, the firm's own programmers can fix it themselves. Microsoft keeps details of its own software so close to its vest that Windows is opaque to programmers, and they have to rely on Microsoft technicians to make repairs.

What really has programmers worried are Microsoft's recent steps to prevent piracy. The firm's new "product activation" policy, rolled out with the October release of its XP operating system, requires customers to register Office XP, Windows XP, Project 2002 and other products with the firm's headquarters in Redmond, Washington. Moving the software to a new computer, or making significant programming changes, requires reregistering it. And how's this for intrusive? From time to time, the software checks your computer's ID to make sure it matches the registration. You might wake up one day to find that your computer has gone into "reduced functionality mode"--it won't save or create new documents. Greg Sullivan, product manager for Windows XP, says that the product-activation policy was designed to be as unobtrusive as possible and will have negligible affects on anyone who isn't breaking the law.

Janak Parekh, 24, a Columbia graduate student, is not reassured. What worries him and many of his colleagues is that Microsoft will continue to tighten the screws, perhaps going so far as to offer Windows and other software as services rather than products. "In the past the product was in a box, and you could take it out and put it on your machine," he says. "If you wanted, you could take the software off the machine and sell it to a friend. Now Microsoft is taking things to the next degree." Microsoft's Sullivan wouldn't say whether the company plans to offer software as services over the Internet. "The whole industry has talked broadly about the idea," he says.

For now, Microsoft's Windows rules the home. Most consumers merely want their computers to work and have no appetite for the tedious process of installing Linux. That may change. Linux hackers from Germany and elsewhere are working on a Windows-like graphical interface for Linux PCs called KDE (for K Desktop Environment). They expect to release it this spring--free of charge.

Microsoft is not taking the threat lying down. It now allows some of its larger corporate customers to tinker with Windows software. In Berlin, Microsoft hired a German lobbying firm to sway the Bundestag. In the end, Microsoft persuaded the Parliament to continue using Windows NE for 5,000 new PCs. But the servers are already in the hands of the enemy.