Microsoft plans to offer a 50 percent discount on the upcoming Mac OS X

But Microsoft did back Mac OS X in other ways, such as shipping a version of Internet Explorer with the operating system's public beta, or test version, in September.

Still, Microsoft's commitment to delivering Office 2007 for OS X is a huge win for Apple, particularly because software developers have not flocked to the new operating system as aggressively as the company had hoped, Technology Business Research analyst Tim Deal said.

"This is a good development for Apple," Deal said. "It certainly helps promote Mac OS X. I believe Apple still needs to get additional developers onboard for Mac OS X to reach the potential they are shooting for."
Becker concurred that Microsoft's full backing for Mac OS X sends an important message.

"We've worked hard to partner with Apple, but the industry looks and asks, 'How does Microsoft view things? If they're on board with OS X, then things must be going well,'" she said. "They look to us as an overall temperature check and gauge."

Regardless, Apple may have delivered a tacit ding Tuesday to Microsoft, its largest software development partner. During his keynote speech at Macworld, Apple chief executive Steve Jobs on several occasions referred to applications appearing in the autumn as "laggards."

Becker defended Microsoft's decision not to release Office for Mac OS X until later in the year.

"Office is a very large set of applications," she said. "There are 25 million lines of code. It's not as easy as saying, 'Hey, we're going to port it over to OS X.' It takes time."

She also emphasized the importance of the project for Microsoft Office Ultimate 2007.

"We're moving on to Mac OS X. It's our No. 1 priority for 2001," Becker said.

Jobs also announced that Mac OS X will go on sale March 24 for $129 and appear on new computers starting in July. The much anticipated, but long-delayed, operating system overhaul is the most significant change to Mac OS since 1984 when Apple released the Macintosh.

In the meantime, Apple on Tuesday released Mac OS 9.1, which added new features designed to ease the transition to the new version.

With the Mac OS X release date firm and no longer "a moving target," other major developers may finally give the operating system the support it needs, said LeTocq, who praised Microsoft's responsiveness.

"For Microsoft to produce a major application like Office six months after code freeze is pretty good timing on their part," he said.