Robot manipulators have gained popularity in the past few decades with successful implementation for intelligent manufacturing in many industrial areas. This is why many colleges are now offering robotics courses. Understanding of a manipulation in robotics is difficult for engineering students because there is no direct and obvious link between what the end-effector needs to do in physical space and what the actuator does to move it robots are usually equipped with internal position sensors in order to measure the relative position of two neighboring links. So, teaching students a robotic manipulator in a laboratory, or training technical staff, is time consuming and may be an expensive task. This article presents an educational tool for robotic with flexible structure and graphical interface by using a new and useful algebra, quaternion algebra. System parameters can be changed easily under different operating conditions. Then, students may perform experiments to verify learned theory and to interpret and discuss the results without a detailed programming knowledge. Six degree of freedom (6-DOF) robot manipulators of general architecture can be solved easily with the help of this educational software with reducing general robot laboratory costs. (C) 2007 Wiley Periodicals, Inc.