CS Colloquium: “How Python Tutor Became a Long-Lasting and Widely Used Academic Software Project,” Philip Guo
September 11, 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
faculty, staff, studentsCommunity 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.
Calendars
The Office of Human Resources is excited to offer HR Connections, a gathering designed to provide a welcoming space where employees can connect with HR, share feedback and engage in open conversations about their workplace experiences. Whether over breakfast or afternoon tea, our goal is to foster meaningful dialogue, build relationships and better understand the needs and perspectives of our campus community.
Each session is intentionally kept small to encourage open discussion while bringing together a variety of ideas and experiences. Gatherings are hosted by Dana Nagengast, along with another member of the HR team. Participation is voluntary, and staff are asked to RSVP in advance.
The Office of Emergency Preparedness and Safety will conduct a practice lockdown exercise on Tuesday, Nov. 3, at 2:20 p.m. A lockdown is an emergency protocol designed to secure and protect individuals who are near an immediate threat. This procedure is used when it may be more dangerous to evacuate a building than to remain indoors.
At 2:20 p.m., HMC will initiate the exercise with an announcement sent via Mudd Alert, which you will receive through your HMC email (and by text message if you’ve chosen to opt in for text notifications using the Mudd Alert Registration form.
The goal of this exercise is to practice securing yourself in your current location should an emergency situation arise. The exercise will conclude no later than 2:30 p.m. with a second Mudd Alert notification indicating that it has ended. If you do not receive the first or second Mudd Alert messages, please proceed with initiating and concluding the exercise on your own wherever you are on campus during this timeframe. Community members will not be asked to evacuate during this lockdown exercise.
For more information, please contact Kelly Salazar, emergency preparedness and safety manager.
Students, faculty, and staff are invited to connect with President Nembhard this semester to share ideas, discuss projects and initiatives, talk about the College’s strategic plan, raise issues affecting the community, or simply connect.
To request a meeting, please choose a preferred slot on this link. Submitting a request does not guarantee an appointment. A member of the President’s Office will follow up with next steps.
Please note:
- Groups should be limited to no more than five people.
- Requests are reviewed as they are received and are subject to change.
Human Resources is excited to continue our Fall Learning Series in partnership with Optum, featuring the theme: “Thriving Through Change: Building Resilience in Today’s Workplace.” These live, instructor-led virtual sessions (via WebEx) are designed to provide practical tools and insights to support your professional and personal well-being through engaging and relevant topics. Each session will be recorded so you can revisit the content at your convenience.
Advance registration is required to attend the live session.
In December 2022, for the first time in human history, a fusion reaction in the laboratory produced more energy than the lasers that started it. That single result—decades in the making—didn’t just answer a physics question. It reshaped how the United States thinks about nuclear deterrence, energy, and what’s possible at the frontier of high-energy-density science. Kim Budil, director of Lawrence Livermore National Laboratory, will discuss this breakthrough and how this fits into the broader national security missions at Lawrence Livermore National Laboratory and beyond.
This talk is part of Professor Tom Donnelly’s course Fusion: A Brighter Future. Speakers will share their expertise on a variety of topics that relate to fusion.
The Community Coffee Break precedes the lecture by Brandon Sorbom, chief science officer and co-founder of Commonwealth Fusion Systems. He has been recognized by MIT Technology Review (35 Innovators under 35) and TIME magazine (World’s Most Influential Rising Stars). Gather with the Mudd community before enjoying an inspiring program that explores the frontier of fusion energy, the ethical responsibilities of technological innovation and Sorbom’s entrepreneurial journey.
At a time when the world is looking for bold solutions to combat climate change, Sorbom is leading a revolution in clean energy. From creating a tabletop fusion device as an undergraduate to leading the ARC Reactor design study as a grad student, Sorbom has exemplified the transformative power of curiosity, rigorous science and a deep commitment to global stewardship.
The lecture begins at 11 a.m.
Join us for HMC Day of Gratitude and Kudos! Take a moment to appreciate the colleagues who make a difference in our HMC community. Stop by for light refreshments, connect with others and pick up Kudos Cards to recognize a faculty or staff colleagues for their support, collaboration, dedication or everyday contributions.
Kudos Cards will be available at the event and are available in the Office of Human Resources in Kingston Hall.
Come by, grab a treat and share some gratitude and kudos!
Students, faculty, and staff are invited to connect with President Nembhard this semester to share ideas, discuss projects and initiatives, talk about the College’s strategic plan, raise issues affecting the community, or simply connect.
To request a meeting, please choose a preferred slot on this link. Submitting a request does not guarantee an appointment. A member of the President’s Office will follow up with next steps.
Please note:
- Groups should be limited to no more than five people.
- Requests are reviewed as they are received and are subject to change.
Submit an Event
Use the Submit Events form to add Mudd community events to the calendar.