I’ve blogged about the switch we made on the Brackets project from Scrum to Kanban and also, more recently, on our use of Kanban at Khan Academy. This article by Grant Ammons mirrors my own experiences:
Peter told me that indeed, many companies follow the same path that we did. They go from no system to Scrum, which teaches them the disciplines they need to properly develop software. Then, as teams fully understand Scrum, its disciplines and rituals, teams have the option to move to Kanban.