Backward Compatibility with SharePoint Portal Server 2001

SharePoint Portal Server 2001 used a different database called the Web Storage System, which is the same database system used by Exchange Server. Many organizations have created SharePoint Portal Server 2001 environments and want to have access to these databases. SharePoint Portal Server 2003 provides the option of installing backward-compatible libraries for document storage. The intention is to then migrate these libraries to the more scalable and manageable SQL- or MSDE-based database structures.

Chapter 8, "Migrating from SharePoint 2001 to SharePoint 2003," provides additional information on backward compatibility.