Built-in SQL Server 2005 Express Support You can develop and debug database objects for your application in Visual Studio 2005—even if you don't have access to SQL Server 2005. SQL Server Express, a free lightweight version of SQL Server 2005, functions as a client database as well as a basic server database. With it you can use the same tools to develop and debug database objects that you use to develop the rest of your application. SQL Server Express replaces Microsoft SQL Server Desktop Engine (MSDE), which was based on SQL Server 2000. SQL Server Express is an ideal choice for Independent Software Vendors (ISVs), server users, non-professional developers, Web application developers, Web site hosters, and hobbyists building client applications. If you need more advanced database features, SQL Server Express can be upgraded to more sophisticated versions of SQL Server. You don't need SQL Server 2005 to develop a SQL Server project in Visual Studio 2005