Systems can be modeled in 20-sim, using equations, state space descriptions, bond graphs block diagrams, and components or iconic diagrams. These descriptions can be fully coupled to create mixed models.
20-sim models are stored in files. The Windows Explorer is used for library management. All 20-sim models are open! You can drag and drop them from the Windows Explorer to the 20-sim editor and change them. You are allowed to store the original and changed models in separate folders to create your own library of models.