[3] Formed as Macintosh Business Unit on January 7, 1997,[4] it was initially composed of over 100 individuals from the existing cross platform Word, Excel, and PowerPoint teams in Microsoft's Office Division, and grew to 180 people the next year, with the addition of the Internet Explorer for Mac and Outlook Express for Mac teams.
During the early and mid 1990s, Microsoft's Word, Excel, and Powerpoint teams simultaneously developed Windows and Macintosh versions of these applications, but after releasing Office 97 for Windows, Microsoft decided, in January 1997, to form a separate Macintosh Business Unit to focus on creating applications optimized for the Macintosh platform.
In August 1997, as part of a broader partnership agreement with Apple, Microsoft committed to continue developing and supporting Macintosh software for at least 5 more years, renewing this pledge on January 10, 2006, at the Macworld Conference & Expo.
[7][8] In October 2008, Eisler was tapped by Robbie Bach to lead all Entertainment Client efforts,[9] and Eric Wilfred became the GM of MacBU.
[10] APEX develops macOS and iOS versions of Microsoft Office and OneNote.