The technical book "Gravity Forward Modeling with a Tesseroid-Based Rock-Water-Ice Approach" offers a comprehensive analysis of the gravitational effects of the Earth's topographic and isostatic masses. It presents the tesseroid-based Rock-Water-Ice (RWI) approach, which enables precise modeling of the Earth's mass composed of rock, water, and ice with variable density values. The author, Thomas Grombein, discusses the theoretical foundations and evaluates the RWI method while also highlighting its applications within the framework of the GOCE satellite mission and the unification of height systems. This book is aimed at professionals and students in the fields of mathematics and natural sciences who are engaged in gravimetry and related geophysical issues.