Sounds similar to the Web Components which allows you to define insertion points in the templates. http://www.w3.org/TR/2013/WD-components-intro-20130606/#inse

Sounds similar to the Web Components which allows you to define insertion points in the templates. http://www.w3.org/TR/2013/WD-components-intro-20130606/#insertion-points http://www.w3.org/TR/2013/WD-components-intro-20130606/#inse... http://webcomponents.org/ http://webcomponents.org/