This illustration shows the OO4O software components (layers).

The first layer contains the Data Aware ActiveX Controls.

The second layer consists of C++ Class Libraries and Oracle Data Control Automation Controllers (VB< Excel, ASP).

The third layer contains the COM/DCOM.

The fourth layer contains the OO40 In-Process Automation Server.

The fifth layer contains the Oracle Client Libraries (OCI, CORE, NLS).

The last layer contains the Oracle Database.