Wikipedia [[defines a Quine|https://en.wikipedia.org/wiki/Quine_(computing)]] as //a computer program which takes no input and produces a copy of its own source code as its only output//.
TiddlyWiki is an unusual example of a practical quine: it is this ability to produce a copy of its own source code that lies at the heart of TiddlyWiki's ability to independently save changes to itself.
