JavaScript Micro-Templating (2008 by John Reisig, mirrored for easy access) http://ejohn.org/blog/javascript-micro-templating/

template_store.html

<script type="text/html" id="item_tmpl">
  <div id="<%=id%>" class="<%=(i % 2 == 1 ? " even" : "")%>">
    <div class="grid_1 alpha right">
      <img class="righted" src="<%=profile_image_url%>"/>
    </div>
    <div class="grid_6 omega contents">
      <p><b><a href="/<%=from_user%>"><%=from_user%></a>:</b> <%=text%></p>
    </div>
  </div>
</script>

<!-- OR -->

<script type="text/html" id="user_tmpl">
  <% for ( var i = 0; i < users.length; i++ ) { %>
    <li><a href="<%=users[i].url%>"><%=users[i].name%></a></li>
  <% } %>
</script>

tmpl.js

// Simple JavaScript Templating
// John Resig - http://ejohn.org/ - MIT Licensed
(function(){
  var cache = {};
  
  this.tmpl = function tmpl(str, data){
    // Figure out if we're getting a template, or if we need to
    // load the template - and be sure to cache the result.
    var fn = !/\W/.test(str) ?
      cache[str] = cache[str] ||
        tmpl(document.getElementById(str).innerHTML) :
      
      // Generate a reusable function that will serve as a template
      // generator (and which will be cached).
      new Function("obj",
        "var p=[],print=function(){p.push.apply(p,arguments);};" +
        
        // Introduce the data as local variables using with(){}
        "with(obj){p.push('" +
        
        // Convert the template into pure JavaScript
        str
          .replace(/[\r\t\n]/g, " ")
          .split("<%").join("\t")
          .replace(/((^|%>)[^\t]*)'/g, "$1\r")
          .replace(/\t=(.*?)%>/g, "',$1,'")
          .split("\t").join("');")
          .split("%>").join("p.push('")
          .split("\r").join("\\'")
      + "');}return p.join('');");
    
    // Provide some basic currying to the user
    return data ? fn( data ) : fn;
  };
})();

usage.html

<script type="text/javascript">
var results = document.getElementById("results");
results.innerHTML = tmpl("item_tmpl", dataObject);
</script>

<!-- PRECOMPILE RESULTS -->
var show_user = tmpl("item_tmpl"), html = "";
for ( var i = 0; i < users.length; i++ ) {
  html += show_user( users[i] );
}