Nordic Dry Deep Mixing (DDM) has been used successfully since the mid-1970s. The first design and execution manual was intended mainly for lime columns, but since the late 1980s, cement has also been used. The method has many possibilities, resulting in much potential for many different ground improvement applications. Research has provided knowledge on design methods and execution techniques. This paper reviews the development in the Nordic countries in the last 20 years of design guides, design in the ultimate limit state, the serviceability limit state, reliability-based design, engineering properties, production control methods, the mixing process, and lessons learned. The paper examines and discusses a selection of theses, reports, and research articles.