Comprehension of concepts and algorithms involved in the robotics field can be improved through the use of an interactive visualization tool. In this paper we present an interactive tool for visualizing and editing motion planning environments, problem instances, and their solutions. Teachers can take advantage of visualization tools to help their students to better understand motion planning and its complexity as well as the different strategies that have been developed to solve the motion planning problem. While the tool we present allows the animation, manipulation, and evaluation of solution paths found by any motion planner, it is specialized for sampling-based randomized planners such as Probabilistic Roadmap (PRM) and Rapidly-Exploring Random Tree (RRT) methods.