HTML and CSS Reference
I wouldn't recommend switching to PHP just for server-side includes, but if you're already using PHP, as so
many sites are, this is very convenient.
These are just a couple of common examples. All but the most basic web servers support some form of server-
side include functionality.
Performance may be marginally slower with server-side includes of various stripes than with static files, but not
usually significantly slower. CPU and local disk speed are rarely the limiting factors on even the highest-volume
web sites today.