The idea of producing a copy of its own source code lies at the heart of TiddlyWiki's ability to independently save changes to itself.

[4] TiddlyWiki is designed for customization and to be shaped according to users' specific needs, perhaps comparable to a high-level programming language.

[citation needed] Each tiddler is stored inside an HTML division that contains the source text and meta data in wiki markup.

The underlying HTML source code (which is not typically directly viewed or modified by end users) would be something like: This same "tiddler" could then be reused in other contexts in the wiki.

Popular community plugins include interactive graph visualization or mind maps with TiddlyMap,[9][10] project management with Projectify,[11] integration with the spaced-repetition-flashcards tool Anki with TiddlyRemember,[12] mathematical typesetting based on KaTeX[13] or MathJax,[14] adding a Disqus-based comment system,[15] and enabling standard Markdown markup.