miniHandlebars.js

String.prototype.template = function(obj) {
  // dot notation path getter for array and obj
  function objPath(obj, path){
    var arr = path.split('.');

    while (arr.length && obj) {
        obj = obj[arr.shift()]
        if(obj === undefined) return '{undefined '+path+'}';
    }

    return ~[Number, String].indexOf(obj.constructor) ? obj : JSON.stringify(obj);
  }
  // parser
  var outstr = '',
      start = -1,
      end = 0;
  while((end = this.indexOf('{', ++start)) > -1) {
    outstr += this.slice(start, end);
    start = end;
    if ((end = this.indexOf('}', start)) > -1) {
      
      outstr += objPath(obj, this.slice(start + 1, end));
      start = end;
    }
  }
  return outstr + this.slice(start);
}

fill = {a:{b:{c:'y'},a:['x', 0, 2]}}

'<div> {not} {a.not} </div> {a.b} <p> {a.b.c} Today at: {a.a.1} </p> {a.a.0}'.template(fill)