Soy profesor de Matemáticas de Secundaria desde 1983 y trabajo con GeoGebra desde 2005. I am Trainer of the GeoGebra Institute of Cantabria (http://geogebra.es/). I have been working with GeoGebra since 2005, actively participating in its development from the Institute of Cantabria. I like everything that represents this program: Free and software quality, international cooperation, good vibes. I teach math, to students between 12 and 18 years.