Flexbook

Derived from the words “flexibility” and “textbook”, Flexbook is a free open source textbook platform that can be used to build and edit collaborative textbooks. Flexbook is an open-content, web-based collaborative model that enables educators to customize content by repurposing what needs to be taught while adhering to the local education standards. Flexbook is maintained by the CK-12 Foundation, a non-profit organization with a goal of reducing the cost of textbook materials for the K-12 market both in the U.S. and worldwide.