Woozle's Wacky Wiki Text Processing Language
Yes, the name is terrible. Suggest a better one...
Main documentation is at http://htyp.org/W3TPL
It ends up largely being useful for a few specific tasks:
- prototyping simple extensions
- managing small extensions that don't need a Special page
- hiding SemanticMediaWiki markup with so I don't have to use the more complex non-displayed format
- report templates
The original plan was to have both tags and a scripting language but so far the tags have done everything I needed them for, so developing the language has been low-priority.