This is a simple way to display files and folders with just one php file.

Just place all the files at the root of a directory structure with the appropriate permissions and you should see something like this by visiting the page :

At some point I realized one of my most favorite web pages were just that default Apache "index of /" thing.
I just needed a few things in addition to it such as the full directory view, file previews, and a bit more customization options, that's why I made this.
I made it for myself but feel free to use it and modify it.