'''[https://en.wikipedia.org/wiki/Event-driven_programming%|%event processing]''' is a [multitasking] technique in which a program learns of events and responds to them. ** See Also ** [event-oriented programming]: [Tcl event loop]: One of the components of Tcl's asynchronous event mechanism Tcl. [Event programming and why it is relevant to Tcl/Tk programming]: [How to mimic event generation without TK]: One approach to providing user-devined events user defined events - something not associated with either window systems or I/O? [windowing system events]: ** Description ** In Tcl, channel events and `[after]` events are sent to the [notifier]. [Tk] sends [windowing system events] to the notifier. The [Tcl C API] provides means for any extension to create its own event types, and also to communicate and process events. <> Concept