Mustache
Scalate’s Mustache is a Scala/Java implementation of the Mustache template language.
Mustache provides logic-less templates which also work inside the browser using mustache.js - so ideal for HTML templates which your designers own. You can use a regular HTML file as the template and let your designer own it, using a little JavaScript file inject the template with sample data. Your Scala/Java developer can then use the template and inject the values on the server side using the real services and domain model.