Rules extensions are implemented as a Microsoft .NET Framework class library, which is a dynamic-link library (DLL), that implements one or more classes. Rules extensions are created using a programming language such as Microsoft Visual Basic .NET, C++, or C#. Microsoft Identity Integration Server 2003 can create a rules extension project in Visual Studio .NET Professional 2003 that implements the IMASynchronization interface for management agents or the IMVSynchronization interface for managing the metaverse. You must then modify the rules extension project so that it performs the actions that you want. For more information, see Rules extensions.