CK-12 FlexBook® textbooks are written by K-12 subject matter experts, educators, and teachers. CK-12 develops its content to align with national, state, and Common Core standards whenever possible, helping ensure materials are accurate, relevant, and classroom ready.
In addition to CK-12 created content, educators and contributors from the community can also customize, adapt, and create their own FlexBook® textbooks using the CK-12 platform.