"It's a false but longtime perception [of] an either/or choice," said Bob Shimp, vice president of open-source for Oracle Corp. In addition to pushing Linux as its preferred database platform, Oracle has snapped up a number of open-source vendors in the past nine months. "Commercial and open-source products are highly complementary," Shimp said. 'Frankly, a lot of people in the open-source community have done themselves a disservice by painting things" as either/or decisions.

Faced with the allure of inexpensive open-source applications among its core customer base of small to midsize businesses, Microsoft has toned down its rhetoric. "It's a myth that open-source and Windows can't work together. Customers just aren't religious about these things," said Ryan Gavin, a director of platform strategy for Microsoft.

Users now have a variety of 12 WAMP packages they can download and install on Windows servers. Take the XAMPP installer, created by Berlin programmer Kai Seidler. Though XAMPP is available for operating systems such as Apple Computer Inc.'s Mac OS X, Sun Solaris and Linux, more than 80 percent of its 3 million downloads have come from Windows users.

Although many open-source vendors continue to make products that work best on Linux, some are also questioning a decision to ignore the huge Windows market.

"As an open-source vendor, we believe in choice," said Ram Venkataraman, director of product management for JBoss Inc. Half of JBoss' customers run Windows. And despite JBoss' acquisition by Linux vendor Red Hat Inc. earlier this year, Venkataraman said the company has no plans to cut out its Windows users.