I built NeonAMP, a browser-based MP3 player that runs as a single PHP file.

You drop index.php into a folder of MP3s and it auto-scans the library, reads full ID3 tags, and stores metadata in SQLite. Playback uses the Web Audio API, including DJ-style crossfading between tracks.

The UI is keyboard-driven and intentionally retro. No frameworks on the frontend, no build step, and the whole thing is under 100KB.

Tech: PHP 8.3+, Vanilla JS, SQLite.

Demo: https://github.com/marchildmann/NeonAMP

Curious what people think and where this could be improved.