CK-12 Foundation
The CK-12 Foundation was created to produce free and open source K-12 materials aligned to state standards. All textbooks—called “flexbooks”— available through CK-12 are free, available online, and customizable.
The CK-12 Foundation was created to produce free and open source K-12 materials aligned to state standards. All textbooks—called “flexbooks”— available through CK-12 are free, available online, and customizable.