摘要:This article describes the educational tool VAST. We designed VAST to be used in compiler and language processing courses. The current version allows generat- ing and visualizing syntax trees and their construction process. The main advantages of VAST follow: it is designed to be as independent from the parser generator as possible, it allows students to visualize the behavior of parsers they develop, and it has an inter- face designed to easily handle huge syntax trees. Finally, we describe two satisfactory preliminary evaluations from the usability and educational points of view.