A method for processing user inputs, comprising: at an electronic device configured to execute software that includes a view hierarchy with a plurality of views: displaying a plurality of views of the view hierarchy; executing a plurality of software elements, each software element being associated with a particular view, wherein each particular view includes one or more input event recognizers, each input event recognizer having: an input event definition based on one or more input sub-events; and an input event handler, wherein the input event handler: specifies an action for a target, wherein the target comprises an object or an application executed by the electronic device; and is configured to send the action to the target in response to the input event recognizer detecting an input event, corresponding to a user input, that corresponds to the input event definition; detecting a sequence of one or more sub-events of an input event corresponding to a user input; identifying one of the views of the view hierarchy, that is a lowest level view in the view hierarchy in which a first sub-event in the sequence of one or more sub-events of the input event occurs, as a hit view, wherein the hit view establishes multiple views in the view hierarchy as actively involved views in which the first sub-event is detected, wherein the actively involved views comprise the hit view; delivering a respective sub-event of the input event to input event recognizers for each view of the multiple actively involved views within the view hierarchy; and at the input event recognizers for the actively involved views in the view hierarchy, concurrently processing the respective sub-event prior to concurrently processing a next sub-event in the sequence of sub-events of the input event at the input event recognizers for each actively involved view in the view hierarchy. displaying a plurality of views of the view hierarchy; executing a plurality of software elements, each software element being associated with a particular view, wherein each particular view includes one or more input event recognizers, each input event recognizer having: an input event definition based on one or more input sub-events; and an input event handler, wherein the input event handler: specifies an action for a target, wherein the target comprises an object or an application executed by the electronic device; and is configured to send the action to the target in response to the input event recognizer detecting an input event, corresponding to a user input, that corresponds to the input event definition; an input event definition based on one or more input sub-events; and an input event handler, wherein the input event handler: specifies an action for a target, wherein the target comprises an object or an application executed by the electronic device; and is configured to send the action to the target in response to the input event recognizer detecting an input event, corresponding to a user input, that corresponds to the input event definition; specifies an action for a target, wherein the target comprises an object or an application executed by the electronic device; and is configured to send the action to the target in response to the input event recognizer detecting an input event, corresponding to a user input, that corresponds to the input event definition; detecting a sequence of one or more sub-events of an input event corresponding to a user input; identifying one of the views of the view hierarchy, that is a lowest level view in the view hierarchy in which a first sub-event in the sequence of one or more sub-events of the input event occurs, as a hit view, wherein the hit view establishes multiple views in the view hierarchy as actively involved views in which the first sub-event is detected, wherein the actively involved views comprise the hit view; delivering a respective sub-event of the input event to input event recognizers for each view of the multiple actively involved views within the view hierarchy; and at the input event recognizers for the actively involved views in the view hierarchy, concurrently processing the respective sub-event prior to concurrently processing a next sub-event in the sequence of sub-events of the input event at the input event recognizers for each actively involved view in the view hierarchy.