A sample application that is designed to illustrate what Microsoft categorizes as key architectural principals of SAAS will be featured. "The app itself is a fictitious HR application," said Tim O'Brien, director of the platform strategy group at Microsoft.

"The functions it provides from an HR standpoint are less interesting than the architectural principals underneath," O'Brien said.

The application is single-instance and multi-tenancy, and guidance is provided on resource-sharing as it pertains to an application.

"Multi-tenancy is a real important architectural concept for companies transitioning to SAAS," because scaling is required, said O'Brien. There are challenges to getting software to scale so another instance of the application is not required, he said. Also featured are rules for security to make sure data does not leak from one tenant or user to another.

The application in question uses Microsoft's C# and managed code technologies. The Visual Studio 2005 platform also is featured, as are Microsoft's SQL Server database and Internet Information Server. Microsoft is intending to show how to deal with SAAS issues using its technologies, but the intent is more to focus on implementation, O'Brien said.