Ductus is a wiki system designed to handle arbitrarily-structured content and a variety of workflows. With Ductus, programmers can easily define classes of structured content, providing rich mechanisms for user interaction. For instance, the Wikiotics project uses Ductus to allow people to collaborate on "language lessons," which can later be used as quizzes or flashcards. Such modes of interaction are not possible with most wikis, which are designed primarily to handle freely-structured text.
