Security
Escaping
See the page on HTML-Escaping to learn how to guard against XSS attacks.
Code Injection
caution
Since Eta compiles to pure JavaScript, you should never run untrusted templates on your server (unless you use a really good sandboxed environment. Eta templates are like EJS, lodash.template, or doT templates: they compile down to straight JavaScript, and you should treat them just like you would untrusted JavaScript code).