Zinnia.js is a porting version of Zinnia(http://zinnia.sourceforge.net/).
Download the language model from https://tegaki.github.io/, and put it under ./zinnia.js/
The default path of model is "handwriting-zh_TW.model", fix it (at the last line of /lib/zinnia.js) if you need another language recognizer.
Open the index.html on Firefox.