Flat World calls its textbooks "open source," although to be clear, the company does not accept contributions to its downloadable copies. The idea is that educators can fork the source, so to speak, for their own needs. There are currently thirty titles in Flat World's , on topics ranging from accounting to marketing to (of course) information systems. Some are complete, but many are still in the process of being written and edited for 2010.

How will Flat World make money from free textbooks? By selling students soft cover textbooks, audio textbooks, and self-printable individual chapters. The company intends to pay royalties to authors from this revenue.

Greenhill managing director Brian Hirsch said in a prepared statement, "The $8 billion annual college textbook publishing market is poised to undergo a radical transformation in the coming years similar to what we've experienced in the music and newspaper industries. College students are digital natives and are demanding the ability to consume and interact collaboratively with educational content anywhere, anytime and anyway."

With schools, students and parents worrying about every dollar, it's possible that a download of Libby Rittenberg's upcoming will become a viable alternative to a $140 new hardcover copy of Paul Samuelson's . Surely Samuelson the economist would understand.