Server Side Includes are still exists. It is in many ways surprising to me that SSI never for more usage that it has, it solves a lot of small scale problem, for minor websites.
mrweasel indeed, exactly what I was thinking. SSI for the head, top, nav, bottom... unique content included. Update to the template is one simple edit.
Taking it a step further with the likes of nginx, cache the response, compress it. done.
