There are a few things here, some more useful than others.
mark (Rust): A quick and dirty Markov chain text generator.
ln-fractal (Rust): A neat fractal I discovered, iterating over ln(-z)/ln(z).
SCL (C): Simple CAS Language, a Computer Algebra System designed to feel as close as possbile to doing math on paper. WIP.
Mandelbrot: Click and drag. Does not yet work on mobile/touchscreen.