Apple noted hitting a milestone of 300 million downloads last August, meaning the service has snowballed in growth since.
Nearly a third (30 percent) of iTunes U traffic now originates from iOS devices. The service, available worldwide in 123 countries, also counts 60 percent of its users as being outside the US.
Apple states that there are now over 1,000 universities actively participating in iTunes U (up from 800 one year ago). Among the most prolific are Open University and Stanford University, which Apple has partnered with in other projects as well. Both have shared more than 30 million downloads with users.
Yale University, MIT, University of California Berkeley and the University of South Florida have all reached 20 million downloads each, while Emory University, Harrisburg Area Community College, Ludwig Maxmillians University of Germany and Oxford University have all surpassed the ten million download mark.
Participating organizations often make their content available free to the public, although some limit access to their own members. For example, Apple itself publishes its Worldwide Developer Conference sessions via iTunes U, but only to registered developers.