Open Source Development with LAMP: Using Linux, Apache, MySQL, Perl, and PHP

SSI is a simple way to embed executable code within HTML. There are other ways (Embperl, Mason, and PHP), which trade the simplicity of this method for power, speed, and flexibility at the price of complexity. SSI is commonly found in the wild, so this chapter should also help you understand the syntax if you see it in someone else's web page.