Mailizar
This paper discusses the differences of students’ achievement between using open-source dynamic mathematics software (GeoGebra) and Geometer’s Sketchpad in learning geometry. There were 43 participants taken from two secondary school classes in Indonesia. The GeoGebra group consists of 21 students, and the Geometer’s Sketchpad group consists of 22 students. The findings show that the use dynamic mathematics software can have positive effect on students’ achievement. However, findings do not show any significant difference between the two groups.