In this chapter, we present our experience, developed in the framework of the MC Squared project, with the design and evaluation of educational digital resources aiming at promoting creative mathematical thinking. The resources, called “c-books” (c for creative), are produced within an innovative socio-technological environment by a community of designers gathering together mathematics teachers, computer scientists and researchers in mathematics and mathematics education. The chapter first discusses what creativity is and outlines the conceptualization of creative mathematical thinking adopted in the MC Squared project. It then presents a c-book aiming at teaching the concept of geometric locus and discusses the design choices providing the c-book with affordances to promote creative mathematical thinking in terms of personalized non-linear path, constructivist approach, autonomous learning, and meta-cognition-based activities, among others. The chapter also presents both experts’ and teachers’ a priori evaluation of the c-book potential to foster creative mathematical thinking in students.