I am a lecturer at the department of Mathematics Education, Universitas Negeri Yogyakarta. I have been using GeoGebra since it was version 3.0. I introduced it to Indonesian mathematics teachers during 2008-2009. I like to explore new technologies for teaching and learning mathematics, especially free software. If you want to contact me, please write to sahidyk@gmail.com. (You may use Markdown to write your message. I like Markdown.)