Unlike the UI frameworks of yore, the Windows Presentation Foundation framework in .Net 3.5 has a full-fledged Commands framework that, besides defining a very good pattern for managing commands, implements an advanced Command routing algorithm adhering to common UI design patterns. The framework advocates the definition of Commands that can be tied to multiple user interface elements like a Menu Item or Toolbar Item. There are plenty of built-in reusable commands already available in the framework (as singleton objects) that can be reused or custom commands can be defined and plugged into the framework and also get associated with UI elements like Buttons or input-gestures like Ctrl+C key, for example.