CS Colloquium: “How Python Tutor Became a Long-Lasting and Widely Used Academic Software Project,” Philip Guo
September 4, 2026 11 a.m.–12 p.m.
Location
Galileo Hall, Pryne
240 Platt Blvd.
Claremont, CA 91711
Contact
Morgan McArdle
mmcardle@g.hmc.edu
909.607.0299
Details
“One Developer, Two Decades and Thirty Million Users Later: How Python Tutor Became a Long-Lasting and Widely Used Academic Software Project”
Since 2009, Philip Guo has been developing Python Tutor, a tool that lets users write code in a web browser and see what happens step-by-step as the computer runs it. The tool visualizes variables, objects, pointers, data structures and stack frames. These visuals help students to debug their homework, teachers to explain concepts and programmers to prepare for job interviews. Despite its name, this tool visualizes code written in Python, Java, C, C++ and JavaScript, which are five of the most popular languages used in both teaching and industry.
Throughout the past two decades, over 30 million students and teachers from over 180 countries have used Python Tutor to visualize over 500 million pieces of code. Guo will reflect upon the design decisions (and non-decisions) he made to turn an off-the-cuff prototype into one of the most widely used pieces of academic software. He will cover three eras of Python Tutor development:
- Act I - Inception, the unique conditions that birthed this idea as a grad student side project.
- Act II - Acceleration, sustaining a decade's worth of user growth as he began his career as a professor.
- Act III - Disruption, when Generative AI both threatens the health of this project and may also be what revitalizes it.
About the Speaker
Philip Guo is a professor of cognitive science at UC San Diego. His research spans human-computer interaction, computing education and human-centered AI for education. He studies how people learn computer programming and data science, and he builds tools to help people better understand code and data. For instance, his Python Tutor educational tool has been used by 30 million students and teachers from over 180 countries throughout the past two decades. Python Tutor received a UIST Best Paper award and the ACM SIGCSE Test of Time award for long-term impact. His other lines of research have received 10-year long-term impact awards from VL/HCC and ISSTA, along with Best Paper awards at CHI, UIST, SIGCSE, VL/HCC, ICSE and ISSTA.
This event is for: faculty, staff, students
Community Connections events provide opportunities for HMC faculty, students and staff to cultivate community, foster open conversations and share important information as together we live out our mission and shape the future of the College.