This is a simple web app that graphs an equation and allows you to pan and zoom around the coordinate grid. It was my winter 2015-2016 break project, developed here and there over two weeks. Interesting bits:
Custom equation editor with exponents, fractions, and other stuff
Live errors inline as you type, sort of like an IDE
GPU-powered anti-aliased equation rendering, handles equations that are impossible to solve
Custom text rendering using subpixel anti-aliasing and GPU quadratic curve evaluation (see the article Easy Scalable Text Rendering on the GPU for a detailed description)
Uses the Skew programming language and the GLSLX compiler, ends up as a few dozen kilobytes of optimized JavaScript
Abuses GitHub's custom 404 handler to make bookmarkable URLs without needing a hosting provider :)