Intersection algorithms for geometry based IT-applications using approximate algebraic methods.: The project address CAD-type intersection algorithms, use of results from complex and real algebraic geometry within CAD as well as better solutions of systems of polynomial equations. Besides a new generation CAD-type intersection algorithms, the project develops a new generation of software for equation solvers combining exact and numeric methods including recursive subdivision. The project has moved state-of-the-art within the topics address, and envision use of the results outside of traditional 3D CAD within application areas in need of solution of systems of polynomial equations.