The Windows Live Messenger Activity software development kit (SDK) contains technical information about how to develop and test single-user and multiuser applications by using the Activity object model. The SDK also provides detailed information about the Windows Live development and testing requirements that your Activity must meet, and how to increase the usage of your Windows Live Messenger Activity application.

This SDK contains the following topics:

• Introduction to the Windows Live Messenger Activity API—An overview of a Windows Live Messenger Activity.
  
• Windows Live Messenger Activity API Process—An overview of the complete Activity application process (from development to release).
  
• Windows Live Requirements for Developing an Activity—Overview of Windows Live requirements that you must satisfy before your application is released publicly.
  
• Developing a Windows Live Messenger Activity—How to develop an Activity using the Windows Live Messenger Activity object model.
  
• Testing an Activity—How to test your Windows Live Messenger Activity in your test environment.
  
• Increasing Windows Live Messenger Activity Usage—How to increase the number of users accessing your Activity.
  
• Technical Reference—Technical reference for developers, including information about including Permission Flags (used when adding special permissions to an Activity) and a brief description of The Activity Object Model.