When facing the problem of teaching the basis of robot control programming to computer sciences students, apart from the syllabus of the course, some other requeriments have to be considered as which is the most appropiate robot, and which are the rigt tools we have chosen for teaching robotics, focussing on the environment that support the practical assignements. We also analyze the reasons that make us chosse each of the tools, making special emphasis on the Libre requirement that we have imposed to every tool we are using. Finally, we present the results and opinions we have got from our students, and the lessons we have learned by using the Libre software approach