compiled.js

var engine = new Eljs({
    , helpers: {
        strong: function(value){/*...*/} 
    }
});
engine.compile("<div>${user.address.length > 0} - ${strong(user.name)}</div>")
engine.parse(json);

eljs.js

var engine = new Eljs({ 
    template: "<div>${user.address.length > 0} - ${strong(user.name)}</div>"
    , json : {
        "user": {
            name: "Christiano Milfont",
            address: [{
                country: "Brazil"
            }]
        }
    }
    , helpers: {
        strong: function(value){return "<b>${value}</b>".interpolate({value:value})} 
    }
});
engine.parse()

eljscompiledwithajax.js

var engine;
$.get("template.html", function(markup){
    engine = new Eljs({
        helpers: {
            strong: function(value){/*...*/} 
        }
    });
    engine.compile(markup);
})

//...
engine.parse(json);

eljswithajax.js

var engine;
$.get("template.html", function(markup){
    engine = new Eljs({
        template: markup,
        helpers: {
            strong: function(value){/*...*/} 
        }
    });
})

//...
engine.parse(json);