You've been looking for a more sophisticated templating engine for JavaScript. Here it is.
E10S is short for “Electrolysis”. Similar to how chemists can use the technique called electrolysis to split water into hydrogen and oxygen, we’re using project Electrolysis to split Firefox into a UI process and a content process. Splitting UI from content means that when a web page is devouring your computer’s processor, your tabs and buttons and menus won’t lock up too.