It breaks down into three distinct components:

Enable mod_include in your httpd.conf file and add the INCLUDES option to your directory settings.

When using SHTML, especially the #exec directive, security remains paramount. Many administrators disable #exec due to potential vulnerabilities. Modern best practices suggest:

If you have Python installed (most new Mac and Linux systems do), you can spin up a basic server, but it does not support SSI by default. For SHTML, you need a simple wrapper.

Using SHTML doesn't mean your development process has to be stuck in the 1990s. Here is how to create a modern workflow for "viewing shtml new" projects: 1. Use a Static Site Generator (SSG) for Development