Part of Microsoft's .Net initiative, HailStorm is the company's plan to provide a single place on the Web where any individual user (who pays a fee) may securely store personal and financial information that can be shared with others when desired (for example, to pay for something at an online store). HailStorm makes use of the Extensible Markup Language (XML) and the Simple Object Access Protocol (SOAP).
The initial set of HailStorm services includes the storing of subscribers' personal information, contacts, locations, profiles, favorite Web sites, and device settings. HailStorm also can provide calendar services and management of inbox items such as e-mail and voice mail. Users pay for all selected services.
An example of a HailStorm service might involve an individual booking an airline flight using an online travel reservation service. With the user's permission, the flight is automatically scheduled into his HailStorm-enabled calendar. If the flight is delayed or canceled, the user is automatically notified. HailStorm services can be accessed from any computer, smartphone, personal digital assistant (PDA), or other Internet-connected device.
Industry commentators and competitors express concerns about Microsoft's ability to keep its users' personal information secure and about the need for an open cross-competitor standard as opposed to a proprietary service that becomes a de facto standard.