This article highlights the progress in the field of radical ring-opening polymerization (RROP) of cyclic ketene acetals for the synthesis of functionalised polyesters, (bio)degradable vinyl polymers, and speciality designed degradable polymers. The method of radical ring-opening polymerization offers the advantage in either making special functional polyesters which are not possible by conventional methods or for making polyesters for special applications where low volume shrinkage is of utmost importance. Furthermore, the beauty of radical ring-opening polymerization is in making a new class of degradable materials called poly(vinyl- co -ester)s. Having ester linkages distributed onto the vinyl polymer backbone is emphasised, no other method can combine vinyl polymer backbone with ester units in a random way. The method has opened new opportunities of using the known biomaterials for degradable applications. Other possibilities and challenges in using this method are making specialised degradable materials like ionomers and polymeric-inorganic hybrid materials, which are also discussed in detail. This article highlights the progress in the field of radical ring-opening polymerization (RROP) of cyclic ketene acetals for the synthesis of functionalised polyesters, (bio)degradable vinyl polymers, and speciality designed degradable polymers.