With both "Cabri" and "Autograph" now venturing into 3D, the dimension that previously was only demonstrated in the classroom with a lot of arm waving and crude wire cages can now be explored dynamically on screen. "Cabri 3D" concentrates on constructions, using the principles of Euclidian geometry, whereas "Autograph" creates objects using a coordinate geometry approach. Both are powerful and useful aids to visualisation in this important area of the curriculum. The inclusion of 3D in "Autograph" allows pupils to explore many of the familiar 2D principles in the more natural 3D space. (Contains 13 figures.)