Thank you for your interest in contributing to development! I am not a p5.js core developer, but you might want to look over the github issues:
and in particular “help wanted” labels.
Rather than trying to understand the entire code base at the beginning – are there particular areas that you are interested in? Animation, sound, typography, 3D…? Or you can pick an area that needs help, and start there.
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You might also be interested in this recent post:
In January, p5.js will be making its 1.0 release! And after nearly 7 years, I’ll be leaving my role as project lead. Our goal is to transition the project to a rotating model of leadership. I have the deepest gratitude and respect for this huge community of contributors, artists, designers, developers, students, teachers, and makers. Thank you. We hope that you’ll join us and support the future of p5!
Here is a post that gives a full overview of our plans:
https://medium.com/processing-foundat…