Agenda is a feature rich MODX calendar extra. It comes with a lot of options like the ability to create and edit recurring events, assign categories and a MODX resource to an event. The location of an event could be displayed with Google Maps. It also supports importing an external iCalendar/XML feed into one calendar, which could be updated with a cronjob. Events could be assigned to a MODX user, usergroup or context.
It is a perfect solution for users looking for an extensive MODX event management calendar or just a well supported MODX calendar component.