The author appears to be using his own functions written in vanilla JS. The Gears page loads a custom Canvas library base.js [1] plus an page-specific gears.js [2]. iOS graphics appears to be an area of expertise [3] for the author.
(P.S. <canvas> is an interesting choice, I had expected <svg> before opening the page inspector. Separately, I love the creative use of TLD in the domain name.)
The author appears to be using his own functions written in vanilla JS. The Gears page loads a custom Canvas library base.js [1] plus an page-specific gears.js [2]. iOS graphics appears to be an area of expertise [3] for the author.
[1]: https://ciechanow.ski/js/base.js
[2]: https://ciechanow.ski/js/gears.js
[3]: https://github.com/Ciechan?tab=repositories
(P.S. <canvas> is an interesting choice, I had expected <svg> before opening the page inspector. Separately, I love the creative use of TLD in the domain name.)