Flat World is an e-textbook publisher company that is used by over one million students in 77 countries. Flat World used to have a free on-demand and customizable textbook model, which was heavily favored by students. However, the company had to drop free access to the textbook platform in 2012. The company launched an adaptive learning and mobile model since then. Flat World has raised $9.5 million in funding led by Bessemer Venture Partners with participation from existing investors Valhalla Partners, Tribeca Venture Partners, Penguin Random House Holdings, and Bertelsmann Digital Media Investments.