A major aspect of the current discussion are learning materials that teachers always have
produced for homework and exercises in their classes. Teachers often include assets they find on
the net or from other sources. With the internet, it is technically easy to make these materials
available for a larger public. Many repositories exist where teachers can upload their materials
and share them with others. Some of these repositories are confined to certain topics and then are
sometimes maintained with the help of an associated institution; others cover all topics relevant
for education and then are most often run by public agencies or private companies. The
production of educational resources with a higher granularity (i.e., textbooks) that typically relate
to a certain curriculum is a more complex enterprise.