This paper presents S-Tutor, a speech-based virtual tutoring system designed for walk-up-and-use situations in teaching environments. S-Tutor is built on top of the CSLU toolkit, a universal speech toolkit that integrates speech recognition, text-tospeech synthesis, and facial animation. By creating a user interaction similar to that of a quiz game show, S-Tutor attempts to educate students in language technology. The system is not bound to this domain and can be easily configured for new types of quizzes. Teachers can add new topics to a quiz using a text editor that automatically translates expected answers to questions into regular grammars for speech recognition.