The Windows Live Admin Center SDK is intended for customers and partners who want to programmatically accomplish many of the administration tasks that are available on the Windows Live Admin Center web site in addition to tasks that are not available on the Web site, such as importing and exporting user lists. The SDK uses the Simple Object Access Protocol (SOAP) remote procedure call (RPC) 1.1 standard for communication between client applications and the web servers for Windows Live Admin Center.

More info: Windows Live Admin Center SDK (MSDN) | Download link