These are huge changes
for a company that built its fortune on proprietary software. Microsoft is more or less conceding that its monopoly days are over, and that the future belongs to open, Web-based programs, much of
which will be ad-supported. The move to more open software is especially positive for Microsoft's enterprise business, which faces mounting pressure from corporate software makers who use open source
technology. The addition of Yahoo will ease the company's transition to a more "Web-centric" (i.e. ad-supported) approach to Internet services.
Of course, Microsoft's own shareholders, who have driven the stock down more than 15 percent since the Yahoo bid, disagree.