A library is a 4D Insider file that contains a set of structure objects. By copying objects to a library file, you can maintain a set of objects commonly used in your databases. This library can be moved to other databases, allowing you to reuse the objects it contains in whichever database or library you want. 4D Insider libraries provide a way to exchange modular 4D structure components within a work group. To create a library, choose New Library from the File menu. A new window will then appear. Notice that it is similar to the window that opens when you open a database with 4D Insider, except that this window is empty. To create a new library, you will need to move objects from one or more databases to the Main list of the library. When you move an object to a library, 4D Insider also moves the objects that it uses. For example, if you move a method, 4D Insider moves any methods that it calls, as well as the commands, variables and all other items used in the method.