Oxford University, The Open University, and Rice University are three of the first schools to release eBooks on Apple's iTunes U, the part of the iTunes Store dedicated to offering free educational content.

The Open University has released 100 free, interactive eBooks and promises an additional 200 titles by the end of the year. The school said its eBooks aren't just digital versions of existing books, but rather books that are designed specifically for the electronic format.

As an example, Martin Bean, vice chancellor of The Open University, said that if you are learning about Schubert, you can hear the music while you follow the score and read the text.

In June, The Open University became the first school to reach 20 million downloads of its material on iTunes U. It now has over 27 million downloads worldwide.

Oxford University joined the eBook release party as it pushed out Shakespeare's entire First Folio. Oxford's Shakespeare contribution is available free from iTunes U.

Oxford said it is also making six plays by contemporaries of Shakespeare available, including "The Duchess of Malfi" by John Webster.

Rice University released 18 of its most popular free textbooks available as part of its open education initiative, Connexions.

The books are available for download on iTunes U in the open ePub format. iTunes U, providing free educational material such as lab demonstrations and lectures, launched in 2007.