Molecular design to control the properties of polymeric materials is gaining increasing attention and applications in materials science in recent years. One of the major scientific challenge is to attain well-defined properties and structural order on the surface of variable materials. With respect to the modification of surfaces, click chemistry in general and specifically cycloaddition reactions (which include 1,3-dipolar cycloadditions as well as Diels-Alder reactions) are preferentially employed and are generating significant interest for the alteration of surfaces. These transformations represent a convenient strategy for the highly efficient coupling of chemical species to solid substrates. In an attempt to address the existing shortcomings of the classical click and Diels-Alder conjugations, a combination of reversible addition-fragmentation chain transfer (RAFT) polymerization and hetero Diels-Alder (HDA) chemistry was recently developed. This book discusses in detail highly innovative protocols based on RAFT-HDA chemistry for the orthogonal modification of solid substrates.