These are intended to open up the world of Web 2.0, where new applications are built using pieces of existing, public Web sites. Web sites stop becoming so much like Web sites as more development platforms. Third-party developers can write applications that tap into the power of say, Google maps, or some powerful MSN service.
Microsoft has already given developers access to some of its Web sites. MapPoint, for example, has had a Web services interface for a few years. But the company is ramping up efforts to make its Web sites programmable and customizable by end users, mirroring the strategies at Google, Yahoo, Amazon.com, eBay and a growing number of Web sites.