Rules extensions are implemented as a Microsoft .NET Framework class library, which is a dynamic-link library (DLL), which implements one or more classes. Rules extensions are created using a programming language such as Microsoft Visual Basic, C++, or C#. Microsoft® Forefront Identity Manager (FIM) 2010 can create a rules extension project in Visual Studio 2005 Professional Edition 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.