droppy is a self-hosted file storage server with a web interface and capabilities to edit files and view media directly in the browser. It is particularly well-suited to be run on low-end hardware like the Raspberry Pi.
TrID is an utility designed to identify file types from their binary signatures. While there are similar utilities with hard coded logic, TrID has no fixed rules. Instead, it's extensible and can be trained to recognize new formats in a fast and automatic way.
miniserve is a small, self-contained cross-platform CLI tool that allows you to just grab the binary and serve some file(s) via HTTP. Sometimes this is just a more practical and quick way than doing things properly.
XBackBone is a simple, self-hosted, lightweight PHP backend for the instant sharing tool ShareX. It supports uploading and displaying images, GIF, video, code, formatted text, and file downloading and uploading. Also have a web UI with multi user management and past uploads history.