"Matters Computational" is a technical book aimed at individuals interested in algorithms and their applications in computer science. It offers a comprehensive collection of algorithms and concepts that are significant for computationalists. The topics covered range from fundamental algorithms and bitwise operations to combinatorial generation methods and fast transformations such as the Fourier transform. Additionally, optimization techniques are presented, and the actual performance of many implemented algorithms is analyzed. The book stands out for its focus on content that is often not addressed in traditional textbooks on algorithms. The implementations are written in C++ and the GP language and are suitable for POSIX-compliant platforms such as Linux and BSD operating systems.