ArcGIS for Server Workgroup also includes ArcSDE support for SQL Server Express. With this level of ArcSDE, you can use SQL Server Express for up to 10 simultaneous Windows desktop users and editors (users of ArcGIS for Desktop Basic, Standard, Advanced, a custom ArcGIS Engine application, AutoCAD, MicroStation, and so on) plus any number of additional server connections from Web applications. (Consult your license agreement for specific information on the number of connections for your implementation.)