Would you like to build applications that can potentially be used by thousands of Microsoft Cloud Customers? This session shows how to develop applications that integrate with Windows Azure Active Directory using the Graph API, a new RESTful interface for accessing directory data hosted in Windows Azure Active Directory. There is a tremendous opportunity for developers to build new applications that integrate with Windows Azure Active Directory, which is the directory for Windows Azure, Microsoft Office 365, Windows Intune, Microsoft Dynamics CRM, and Global Services Monitoring customers. We present the directory data model, and demonstrate how easy and intuitive it is to write an application that connects with Windows Azure Active Directory. We also show integration with single sign-on with Azure Active Directory, and how a Multi-tenant App could be built, and offered to customers. Microsoft .NET, Java, and PHP examples are demonstrated.