With its just-fielded Google Calendar service, Google is going head-to-head with a number of other companies with lengthier histories in this space, including archrival Microsoft.
Microsoft has offered calendaring as part of Outlook and Hotmail for years. Recently, Microsoft added more calendaring offerings to its stable.
It introduced a new calendaring facility that it is baking into the beta and final releases of Windows Vista, as well as new calendaring functionality as part of Windows Live Mail, the successor to Hotmail known by the code name "Kahuna."
Theres also a third-party-developed Windows Live gadget called "Windows Live Calendar" that is available for download from Microsofts Gadget Gallery site.
"Microsoft has a long history and deep investments in calendaring," said an MSN spokesman. "We have had consumer calendaring services with MSN for years, as well as consumer- and enterprise-level calendaring with Outlook and Exchange."
Like other AJAX calendaring applications, the calendar that is part of the Windows Live Mail beta includes basic sharing and alert capabilities, MSN officials said.