Ask HN: What's the most creative 'useless' program you've ever written?

I like inserting art, like the header to https://simonsarris.com

A village pops up. There is no point to it. You can click to make more houses. You can right-click to drag things around. When I touch it again I think I'll add a sun and moon that track the time of day for wherever the user is located. Actually the footer has art too, each page has a semi-randomly assigned illustration from public-domain (old) art that I've found. Like drawings from James McNeill Whistler, for instance. I use his illustrations in 'useful' websites too.

Actually, I experimented with the sun/moon a few years ago, in this version: https://simonsarris.github.io/simeville/

If you left-click drag the sun downwards, you'll see the moon come up. That one is open source, but the code is quite slapdash compared to the new one. Also you have to click ITS TIME TO BUILD to get the buildings.

In general I think websites could be a lot more pretty (gorgeous even), silly, interesting, and a lot less corporate chic than they currently are.

For me it is for instance my involvement in the demo-scene in the 90’s.

A concrete example is Nikki, a demo released in 96 and captured (with some technical difficulties) by a friend here https://youtu.be/t8o-uuq73UU?si=4dlTla0s2mDCVzCK

Working on anything “useless” is profoundly life changing and “useful” on the long run!

Only now am I able to do more similar stuff (my current research is around music + code + lightning and videos, this time connected to real life performances), and it is massively pleasurable (and also likely one of the most technical types of work I will be working on for now!)

Given that this site is called "Hacker News", it's worth mentioning that '"useless" programs - pieces of code that serve no practical purpose but are fun, creative, or challenging to write' is one of the central definitions of ”hack”.

I've written some: a programming language interpreter based on Abadi and Cardelli's untyped ς-calculus; a two-kilobyte web server in assembly (which accidentally did turn out to be useful); a self-compiling compiler from a sort of Forth dialect to i386 ELF executables; a translator from standard English orthography to an ASCII alphanumeric phonetic orthography I designed; a one-kilobyte programming language interpreter with dynamic multimethod dispatch and pattern-matching; a base-3 calendar based on the Sierpinski triangle; a C interpreter in Python I used for bytebeat livecoding; several implementations of Tetris, one of which is a 2K ARM executable; an operating system for ARM consisting of five instructions; a few raytracers; a Space Invaders game; a minimal roguelike in Forth; a library for manipulating Boolean functions as Zhegalkin polynomials; many symbolic differentiators; a sort of polyrhythmic drum machine called Pygmusic; a parametric CAD system in PostScript for laser-cutting MDF; 3-D rotating objects in ASCII art in 20 lines of Python; Karplus-Strong string synthesis in one line of C; an audio PLL in one line of C; an RPN calculator with forward-mode automatic differentiation; a slide rule in Tcl/Tk; a port of the logic-programming EDSL μKanren to OCaml; several fractal renderers; a decoder for the "gridfonts" Hofstadter and his research group designed; a Hershey font decoder; several maze generators; a generator for balanced-nonary multiplication tables; a vocoder; a Doom-like first-person raycaster; a teapot mod for the Minetest game; a compiler for a subset of Scheme written in itself; etc.

A lot of this is in http://canonical.org/~kragen/sw/dev3/ which you can clone with Git. I'd be happy to elaborate on any of these if you are interested.

I made a small C program that would use GMP to generate a prime number from a bmp image. I was inspired by a Youtube video but I can’t remember what it was anymore.

https://github.com/Fethbita/BMP_to_Prime

I like having this kind of animation on my homepage, too.

Currently I just have an animated GIF background, but I've had some animated ASCII art in the past.

I'm currently working on animating a fractal drawn with HTML Canvas.

Your houses and pencil style are very cute, I feel inspired to make something similar.

I'd like if clicking in the same place would grow whatever's there.