awesome-self-reference

A number that is its own prime factorization, that is 13532385396179 = 13 × 53² × 3853 × 96179.

This sentence is false.

Conway's Game of Life running inside Conway's Game of Life using OTCA metapixels.

Does the set of all those sets that do not contain themselves contain itself?

The unique number whose digits equal its continued fraction coefficients.

A formula that visually represents itself when graphed at a specific location in the (x, y) plane.

The LISP interpreter written in LISP.

A Ruby program that generates Rust program that generates Scala program that generates (through 128 languages in total) REXX program that generates the original Ruby code again.

A Ruby quine that remains a quine after any one of the characters in its source code is removed.

A technique for producing a self-compiling compiler - that is, compiler (or assembler) written in the source programming language that it intends to compile.

A higher-order function fix that, for any function f that has an attractive fixed point, returns a fixed point x of that function.

A PNG image of the ouroboros that displays its own MD5 hash.

A sentence that describes itself in the sense of providing an inventory of its own characters.

A rule of language or linguistic style, humorously written in such a way that it breaks this rule.

An acronym that refers to itself.

A curated list of examples of self-reference in art, science, and technology, which includes itself.

A tweet that quote tweets itself.

Snapshots of The Internet Archive stored in The Internet Archive.

An article about Wikipedia on Wikipedia.

The effect of a picture recursively appearing within itself, in a place where a similar picture would realistically be expected to appear.

A formal technique of placing a copy of an image within itself.

A painting by René Magritte.

A painting by Norman Rockwell.

"It always takes longer than you expect, even when you take into account Hofstadter's Law".

The world's largest model railway in Hamburg, Germany has a model of itself in its model of Hamburg.

The village where Untitled Goose Game takes place contains a small model version of itself, and also a tiny version of the model inside that.