Microsoft has never been a big supporter of the open-source movement, but yesterday's announcement of an agreement with Zend, maker of open-source PHP tools, is one more signal of a shift in Redmond's stance.

"Microsoft has already been moving in this direction for some time," said Joseph Wilcox, a senior analyst and Microsoft expert at Jupiter Research.

Zend, which bills itself as "the PHP company," makes development products based on open-source PHP code. PHP is one of the world's most popular programming languages for Web sites and Web applications, and competes with Microsoft's ASP.NET and other technologies, such as Perl.

And while a majority of PHP programmers work on Microsoft platforms, PHP and Microsoft's servers -- including Windows Server 2003 and Internet Information Services (IIS) -- have never worked together as well as PHP and the Apache Web Server. Apache runs on Linux and Unix and is widely believed to be the world's most popular Web server.

The Specifics

Under the terms of their new agreement, Microsoft and Zend will improve the way that PHP works on Windows servers. First, Microsoft will build and release an add-on to IIS called FastCGI, which should provide a more stable interface between PHP and IIS.

In turn, Zend will tweak PHP to work better with Microsoft products, and submit those revisions to PHP user groups for comments under the PHP license. Zend also will build a testing lab for Windows and use it to ensure that PHP works on current and future versions of Windows servers, including Longhorn.

In a prepared statement, Microsoft's Bill Hilf, general manager of technical platform strategy, said the common goal was to simplify the use of Windows servers for Web applications "regardless of the development model they employ."

If You Can't Beat 'Em

Microsoft has slowly -- and at times silently -- been moving toward open-source awareness, said Jupiter's Wilcox. He noted that Microsoft has tweaked many of its Web sites, including Soapbox, its alternative to YouTube, to be "technology agnostic."

Now, users of open-source Mozilla products, such as the Firefox Web browser, can view Soapbox just as well as those who choose Microsoft's Internet Explorer.

"With respect to open source," said Wilcox, "the reality is that businesses are absolutely using Microsoft technology in certain areas, but not in others, and Microsoft is embracing that."

According to Wilcox, Microsoft wants traction against competing products in the increasingly vital sphere of Web servers and Web software. "They don't want to lose that customer to Apache," he said.