Macworld Expo Microsoft wants you to know that it's not just the Mac that's holding a 25th birthday party: 2009 marks the 25th year that Redmond has developed software for Apple's quarter-centarian computer.

The Apple/Microsoft relationship has had its rocky moments, to say the least. But the fact remains that Microsoft has consistently been at the top of the heap among Mac-productivity software publishers since the company released Word 1.0 for Mac in 1984.

In the Beginning, There Was Word

Although it was Microsoft's first productivity app for the Mac, Word didn't originate at Microsoft. It's earliest ancestor was Bravo, arguably the first WYSI(sorta)WYG word processor, developed at Xerox PARC in 1974.

Seven years later, Microsoft hired Charles Simonyi, one of Bravo's lead developers, to head-up work on Word's most-direct progenitor, Multi-Tool Word, which was released in the spring of 1983 for Xenix, Microsoft's sole foray into the world of Unix.

In 1984, Multi-Tool Word was ported to the Apple's new Mac, and Microsoft has been publishing productivity software for the Mac ever since.

For its next trick, Microsoft released Excel 1.0 in 1985. Then it shipped PowerPoint 1.0 in 1987, which remained a Mac-only app until 1990.

Although obviously influenced by previous spreadsheets such as VisiCalc, Lotus 1-2-3, and Microsoft's own MultiPlan, Excel was developed inside Microsoft. After a brief vaporware scare from Lotus Jazz, Excel settled into its role as the Mac's go-to spreadsheet.

PowerPoint was developed by Forethought of Sunnyvale, California, just up the road from Apple's Cupertino home. Originally called Presenter, that name was changed by Forethought to PowerPoint when trademark problems surfaced.

Forethought and PowerPoint were bought by Microsoft in 1987, and in 1989 Microsoft bundled its three Mac apps together in the first version of Office for Mac: Word 4.0, Excel 2.20, and PowerPoint 2.01.