Drawing with zero-width characters

It does not work on iOS Safari at all, it should show a warning at the top saying so

I agree, a few screenshots would be helphful for users of unsuported browsers.

Another thing in the category of abusing font capabilities is Harfbuzz (OpenType engine) WASM, which if compiled into an application allows fonts to basically run any code. A few examples are an LLM or a Tetris font. Apparently this WASM support is in the font rendering for Chrome and Firefox supposedly.

I was really tempted to try to use it to make a Harfbuzz OS.

https://fuglede.github.io/llama.ttf/

Also,

Tۜۜۜۜۜeۢۢۢۢۢsۛۛۛۛۛtۙۙۙۙۙiۚۚۚۚۚnۨۨۨۨۨg۫۫۫۫۫

T◌ۜ◌ۜ◌ۜ◌ۜ◌ۜe◌ۢ◌ۢ◌ۢ◌ۢ◌ۢs◌ۛ◌ۛ◌ۛ◌ۛ◌ۛt◌ۙ◌ۙ◌ۙ◌ۙ◌ۙi◌ۚ◌ۚ◌ۚ◌ۚ◌n◌ۨ◌ۨ◌ۨ◌ۨ◌g◌۫◌۫◌۫◌۫◌۫◌

|ۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗۗ|ۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘۘ|ۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙۙ|ۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚۚ|ۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛۛ|ۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜۜ|۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟۟|۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠۠|ۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡۡ|ۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢۢ|ۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧۧ|ۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨۨ|۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫۫|۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬۬|ۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤۤ.

Tۜۜۜۜۜeۢۢۢۢۢsۛۛۛۛۛtۙۙۙۙۙiۚۚۚۚۚnۨۨۨۨۨg۫۫۫۫۫

Author's specific examples: Aۜۢۛۜۢۛۜۢۛۜۢۛۜۢۛ Bۙۚۨ۫ۙۚۨ۫ۙۚۨ۫ۙۚۨ۫ Cۣۣۣۣۣۣۣۭۭۭۭۭۭۭ Dۣۭۣۭۣۭۣۭۣۭۜۢۜۢۜۢۜۢۜۢ

Further Tॅॅॅॅॅeॆॆॆॆॆsेेेेेtैैैैैiॉॉॉॉॉnँँँँँgॄॄॄॄॄ with oೄೄೄೄೄtೋೋೋೋೋhೌೌೌೌೌe్్్్్rඃඃඃඃඃ lិីឹឺុូួើឿៀេែៃោៅំះៈ៉៊់៌៍៎៏័៑្៓aᢅᢅᢅᢅᢅᢆᢆᢆᢆᢆn଼ାିୀୁୂୃେୈୋୌ୍ୖୗg֒ ֓ ֔ ֕ ֖ ֗ ֘ ֙ ֚ ֛ ֜ ֝ ֞ ֟ ֠ ֡ ֣ ֤ ֥ ֦ ֧ ֨ ֩ ֪ ֫ ֬ ֭ ֮ ֯ ְ ֱ ֲ ֳ ִ ֵ ֶ ַ ָ ֹ ֻ ּ ֽuﬞ ﬞ ﬞ ﬞages .

Now attempts with superscript A Bⷠⷡⷢⷣⷤⷥⷦⷧⷨⷩⷪⷫⷬⷭⷮⷯⷰⷱⷲⷳⷴⷵⷶⷷⷸⷹⷺⷻⷼⷽⷾⷿꙴꙵꙶꙷꙸꙹꙺꙻꚞꚟ Cꙷꙷꙷꙷꙷꙷꙷ Dⷶⷠⷡⷢⷣⷷⷤⷥⷦⷧⷨⷩⷪⷫⷬⷭⷮⷯⷰⷱⷲⷳⷻ E F G H (Some kind of work, U+32x thru U+34x were E-G, U+20Dx was H, work on websites, just won't copy/paste to forum)

Edit: Apparently, you cannot write direct html entities.

Edit: And you cannot directly write the characters either. Rendering seems rather finicky on Firefox, while Chrome seems somewhat consistent.

Actually, on Chrome, copying the characters directly "kind of" worked. They're still shown next to each other, yet some of them combined and actually created towers.

Writing the HTML entities on a private webpage and then copying them over seemed to work the best.

Edit: Apparently, at least some of the Devanagari unicode behaves similarly.

Edit: Several other languages combining marks taken from https://www.cogsci.ed.ac.uk/~richard/unicode-sample-3-2.html and https://www.compart.com/en/unicode/category/Mn seem to also work.

After further testing, Both browsers are really finicky, and have wildly different interpretations of pasting combining characters directly, vs writing HTML entities, vs copying the combined stack from an existing site.

firefox refuses to render these and maxes out my CPU fans xD