Google entices Microsoft users with a new free online calendar service. (file photo)

BEIJING, April 14 (Xinhuanet)-- Google Inc. released a free online calendar service on Thursday, posing a direct challenge to other calendar systems such as Microsoft Outlook and Yahoo Calendar.

The latter, being the No. 1 Web calendar service in the United States, was introduced in 1998 and has changed little in substance in recent years.

But Google's calendar software differs from others significantly. First and foremost, it can allow users to maintain several kinds of calendars, for work, for social life, and for children's schedules.

Secondly, it is based on open software that can be integrated with other software services and Web sites.

It also enables users to determine who else can view their calendar information by entering permitted viewers' e-mail addresses.

"We enable the user to create multiple calendars, share them with other people and overlay Web calendars back on the user's own calendar," Google product manager Carl Sjogreen said.

Google Calendar is available to all users with a Google account. Its trial version is being offered in English at the moment. But in coming months, Google will translate the calendar into multiple languages, the company said.

Google said that it tried to play "nice" and made its calendar compatible with those of its rivals. Enditem