Nunjucks is a full featured templating engine for javascript. | kernicPanel | Scoop.it
It is a direct port of the Python-powered jinja2 templating engine and aims to be feature-complete with jinja2. It supports server and client-side rendering. View on github.

It was born out of frustration with other javascript templating engines. The most popular ones either are ugly and don't abstract enough (EJS) or have too different of a syntax (Jade). The only other project like this is jinjs, which has been abandoned.