Is there a way to make an HTML page include php, but not have a .php extension? I want to "include" my headers
<p>Some pages seemingly don't have a .php extension, but they have server-side stuff in them. Or am I completely wrong with that?</p>

<p>Basically, I'd love to have include statements for my header and footer, without having to copy and paste changes into every HTML document, but rather update the one. Can I do this without making the page .php?</p>

<p>What's the best way to include those?</p>
