The birth of Cabri ------------------
A wide range of software packages gained a foothold in France, most designed for education and used by school and university students as well as teachers. The most notable—the pioneering program—is Cabri Géomètre, created in 1985 on the initiative of Jean-Marie Laborde, a mathematician, computer scientist and researcher in discrete mathematics, and a small team working with him at the time. Originally a "Cahier de Brouillon Interactif" (Interactive Rough Notebook) for geometry, the software allowed users to explore the properties of geometric objects and their interactions.
Developed for secondary-school students, the commercial program Cabri—as it soon came to be known—offers a notable advantage for teaching: move any basic element of a drawing with the mouse, and the diagram changes shape while preserving the construction constraints. If a parallelogram has been constructed by drawing parallel lines or by using the shared midpoint of its diagonals, moving a vertex may alter the angles or side lengths, but the figure remains a parallelogram. Cabri is thus an educational tool that helps students acquire the skills needed to construct geometric figures. It lets students actively interpret numerical data and geometric symbols, helping them develop their understanding of both algebra and geometry.

Modeling Chambord's double staircase using Cabri Géomètre 3D.