A truly single-file, no-database, drop-in PHP media gallery. Everything else wanted a database setup, or was just way, way outside the scope of what I wanted: just cleanly serve images, video, audio, pdf and text assets using the filesystem for organization. Don't overthink the capabilities of this: you won't find tags, comments, or much of anything outside of directories and filenames. I keep a fresh copy in the /build directory of the master build. Literally just copy/paste, edit the config block pointing to a media path (it defaults to /media), and off you go. If a directory has an readme.md file, it will be rendered below the directories and media. Will create and serve basic thumbnail images from the .data directory.
Just show media.