It’s a picture! It’s a program!! It’s Piet!!! by Anjana Vakil What if you didn’t write a program, but drew it instead?!? What if you could learn about programming languages and models of computation by playing with pixel art?!? Spoiler alert: you can!! Piet, named after the artist Piet Mondrian, is an esoteric programming language, aka “esolang”, where programs are abstract pixel art(!), blocks of color are data(!!), and programmers use variations in color to send instructions to a stack-based interpreter to compute… anything!!! (Really, it’s Turing complete! You can even write an interpreter for another language in it!!) Let’s learn how Piet works through a visual exploration of the basic concepts of the language, take a look at a few amazing programs, and see how this pixel-perfect esolang can teach & inspire us to learn more about the art of computing (pun intended!). Anjana suffers from a chronic case of curiosity, which led her from philosophy to English teaching to computational linguistics to software development. As a developer advocate at Observable, these days she codes & teaches from her home base in San Francisco; in the before-times, you could find her speaking at events around the world. She loves to share the joy of programming and advocate for a more diverse, equitable, and ethical tech industry. Ask her about the Recurse Center & Outreachy, she’s an alumna of both!