p5.js is a JavaScript library for creative coding, providing a comprehensive API for 2D/3D graphics, animation, interaction, and data visualization. It is designed for artists, designers, and educators, with a focus on accessibility and beginner-friendly error messages. The architecture is modular: a core module registers addons for color, shape, WebGL, DOM, I/O, math, and more. It supports multiple renderers (2D canvas, WebGL 3D, experimental WebGPU) and includes a sophisticated shader compilation pipeline (strands) that transpiles a p5.js-like DSL to GLSL/WGSL. The codebase is well-structured with extensive unit and visual regression tests, and it follows a consistent addon registration pattern for extensibility.