filebrowser provides a file managing interface within a specified directory and it can be used to upload, delete, preview, rename and edit your files. It allows the creation of multiple users and each user can have its own directory. It can be used as a standalone app or as a middleware.
Sharry allows to share files with others in a simple way. It is a self-hosted web application. The basic concept is: upload files and get a url back that can then be shared.
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.