By Matt Berger, IDG News Service

An advertising campaign funded by Unisys Corp. and Microsoft Corp. aimed at converting Unix users to their high-end server products hit a sour note yesterday.

The campaign, dubbed "We Have the Way Out," is intended to promote Unisys' ES7000 Enterprise Server, which is capable of running a data center version of the Windows 2000 operating system. That combination of Unisys hardware and Microsoft software is designed to compete against more widely used Unix-based server products from Sun Microsystems Inc., Hewlett-Packard Co. and IBM.

The two companies claim in some advertisements that unlike their products, Unix "makes you feel boxed in" and "ties you to an inflexible system."

As it turns out, a Web site built to promote the advertising campaign is itself running on the FreeBSD operating system, a free version of Unix, according to Bath England-based Netcraft Ltd., which monitors the software and operating systems used by Web site administrators. In addition, Netcraft revealed that the campaign Web site is hosted on an Apache Web server, another free piece of software developed by open-source programmers.

Representatives from Microsoft and Unisys yesterday wouldn't comment on the campaign. A representative from Blue Bell, Pa.-based Unisys confirmed that the two companies are sponsoring the effort and said the Web site was set up by a third-party company, which is also responsible for hosting the site.

Other attempts by Microsoft to disparage competing operating systems haven't worked in the past. Last year, Microsoft led a public assault against open-source software, including the Linux operating system, warning that users adopting the operating system could tie up their intellectual property due to the license that governs its use.

Known as GNU GPL (General Public License), the software license requires users to publish the source code of any piece of software developed under the license.

As it turned out, Microsoft was using some open-source software to run its free e-mail service, Hotmail. It was also revealed that Microsoft uses open-source software in a tool that it distributes to customers for running Unix applications on the Windows operating system.

While Unisys yesterday downplayed the significance of the revelation about the anti-Unix campaign, first reported in the The Wall Street Journal, the latest marketing hiccup exemplifies the market conditions Microsoft must overcome to win over customers who historically look to Unix vendors.

Microsoft may have an uphill battle, but it's making progress in its efforts to convince large enterprise customers that its server software can be reliable and sturdy enough to match Unix systems, said Tom Manter, director of server software research at Boston-based Aberdeen Group Inc.

"Unix has pretty much