The Aplusix-editor: A new kind of software for the learning of algebra The first part of the paper presents our conception of a new kind of software for helping students to learn algebra. Such software has three main characteristics. First it includes an advanced editor that allows the student to build easily algebraic expressions. Second it reifies the student’s reasoning as a tree. Third it verifies the student’s calculations. In the second part, we present the Aplusix-Editor, a system of that kind that we have realised, and we describe the first tests of this system.