"Google Spreadsheet, which will be made available on a limited test basis, follows Google's March purchase of a company offering a Web-based word processor called Writely.
The two Google Web-based applications represent possible challenges to Microsoft Corp.'s core personal-computer software business. Microsoft's Word and Excel dominate the word processing and spreadsheet markets.
Google's forays are part of an explosion of Web-based applications that over time may threaten Microsoft's hold on PC software, and are stirring the Redmond, Wash., company to invest in its own Web services. Microsoft has been building out online services associated with its Windows and Office programs since late last year in the hope of grabbing more online advertising."