Still using Processing after 10 years! I do some Android prototyping and also this P5.js sketch which takes images and displays a virtual persistence-of-vision effect on my site (https://magicpoi.com - login is for my Patreon members only at the moment).
Here is what the real thing look like:
Pretty close, right? The effect is done with lots of MATH (sin, cos) and pixel by pixel updates so it is SLOW - but it works!