diff --git a/MVVM/ViewModels/BaseViewModel.ps1 b/MVVM/ViewModels/BaseViewModel.ps1
new file mode 100644
index 0000000..75edea3
--- /dev/null
+++ b/MVVM/ViewModels/BaseViewModel.ps1
@@ -0,0 +1,36 @@
+Add-Type -AssemblyName PresentationFramework
+
+# INotifyPropertyChanged Basisklasse fuer alle ViewModels
+Add-Type @"
+using System;
+using System.ComponentModel;
+using System.Windows.Input;
+
+namespace FirefoxAddinManager {
+
+    public class ObservableBase : INotifyPropertyChanged {
+        public event PropertyChangedEventHandler PropertyChanged;
+        protected void OnPropertyChanged(string name) {
+            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
+        }
+    }
+
+    public class RelayCommand : ICommand {
+        private readonly Action<object> _execute;
+        private readonly Func<object, bool> _canExecute;
+
+        public RelayCommand(Action<object> execute, Func<object, bool> canExecute = null) {
+            _execute    = execute ?? throw new ArgumentNullException(nameof(execute));
+            _canExecute = canExecute;
+        }
+
+        public event EventHandler CanExecuteChanged {
+            add    { System.Windows.Input.CommandManager.RequerySuggested += value; }
+            remove { System.Windows.Input.CommandManager.RequerySuggested -= value; }
+        }
+
+        public bool CanExecute(object parameter) => _canExecute == null || _canExecute(parameter);
+        public void Execute(object parameter) => _execute(parameter);
+    }
+}
+"@ -ReferencedAssemblies PresentationFramework, PresentationCore, WindowsBase