Flat World Knowledge, an open source textbook publisher that offers its texts for free online, while selling ancillary products based on them, has secured an undisclosed amount of funding from Random House Inc. The amount of the investment was not disclosed and it is separate and additional to the $15 million in funding Flatworld Knowledge received in January from Bertelsmann Digital Media Investments, a unit of Bertelsmann, RH’s parent company, and Bessemer Venture Partners.

Jeff Shelstad, Flat World Knowledge CEO and co-founder, said the Random House investment, “sends a strong message to our customers about the quality of our authors’ work, and the long-term viability of our business model. This is great news for our company and for the future of higher education publishing.” Flatworld Knowledge textbooks have been adopted by more than 1600 professors at more than 900 colleges. In addition, FWK texts are used in 44 countries by more than 100,000 students internationally.

Random House chairman and CEO Markus Dohle, called Flat World Knowledge a “transformative company in higher-education publishing” and said, “We share a strong drive to make high-quality academically-oriented content widely available and affordable for students and educators, and we welcome the opportunity to invest in Flat World's growth." RH will have no operational rolein Flat World.

Flat World Knowledge offers a new model for textbook publishing that makes educational content easier to customize for professors and more affordable to students. The company uses veteran academic authors to produce its textbooks under a creative commons licenese that allows professors to add notes and customized content to the text and then publishes the texts online for free. FWK generates revenue through the sale of digital and print products—from podcasts and PDFs to interactive study guides, low-cost print editions and e-books for a variety of mobile devices—based on its free textbooks. The company has also pioneered the use of site licenses at Virginia State University as well as the Ohio university system, which gives students complete access to FWK’s digital content for a very low student fee.