When Bob Hecht joined Informa as its vice president of content strategy, he dreamed of rebuilding the British technical publisher's infrastructure using Linux and open-source technologies. But with Microsoft Windows entrenched throughout the company, Hecht settled on a more pragmatic hybrid: an open-source content management server from Alfresco Software, backed up by open-source applications MySQL, Apache Tomcat and JBoss -- all running on Windows Server-based hardware.

"Would I want to put it all on Linux? Yeah, that's the geek in me," Hecht said at the O'Reilly Open Source Convention last week. "But the Alfresco application doesn't necessarily run better under Linux."

And although the Windows licenses may make the initial costs a little more expensive for Informa, not having to rehire or retrain existing IT staff makes "the whole thing a wash," he said.

While open-source applications such as the OpenOffice productivity suite and the Firefox Web browser are aimed at Windows users, back-end software used by businesses is a different matter. Both Microsoft and open-source vendors have traditionally portrayed the choice of whether to use their software as a black-and-white decision. Choose Microsoft Windows' all-inclusive .Net infrastructure, or run the LAMP stack of applications, which includes Linux, the MySQL database, the Apache Web server and one of three programming languages starting with the letter P: Perl, Python or PHP.

One choice promises easier management at a higher price. The other offers lower costs and better security -- at the cost of more complexity.

But Hecht is part of a growing wave of IT users opting for a third way some have dubbed WAMP (Windows, Apache, MySQL and Perl/Python/PHP). They say it provides the best of both worlds.

"It's a false but longtime perception [of] an either/or choice," said Bob Shimp, vice president of open-source for Oracle. 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's Mac OS X, Sun Solaris and Linux, more than 80 percent of its 3 million downloads have come from Windows users.

Forty percent of MySQL downloads are by Windows users, and more than a third of SugarCRM users run that software on Windows.