Mandatory: Applications for Windows SharePoint Services

These application templates are tailored to address the needs and requirements for specific business processes or sets of tasks for organizations of any size. The applications are the first out-of-box custom scenarios for the Windows SharePoint Services platform, though they also provide a starting point for partners and developers looking to build deeper Windows SharePoint Services solutions.

http://www.microsoft.com/technet/prodtechnol/sppt/wssapps/default.mspx