An annotated Busy Beaver program in Turing Paint
One doesn't so much write a Turing Paint program as scribble it, preferably in MSPaint.
Think of it as Piet meets the Turing Machine. Where Piet uses colors to indicate commands, it also essentially a Funge, where the instruction pointer is sent left or right, up or down via a command (indicated with a relative change in color). In Turing Paint, those directions are determined by paths marked in black, similar to the lines of an AsciiDots program.
However, the real charm of Turing Paint is in the crudeness of its programs' visual design, where programs can be quickly scribbled doodles, so long as the logic is correct. In fact, the more basic the editing tool, the better: anti-aliasing, on by default in most imaging programs, causes interpreter issues. Turing Paint creator Byron Knoll, a software engineer at Google, suggests writing programs in JSPaint, which simulates MSPaint in the browser.
This entry originally appeared at esoteric.codes/blog/turing-paint, and may be a summary or abridged version.