FileBrowser Quantum is an open-source, self-hosted web file manager that transforms any directory tree or mounted storage volume into a fast, searchable cloud drive accessible from any browser. You can mount multiple independent filesystem sources at once and apply custom include or exclude rules to keep sensitive system folders hidden from everyday browsing. A background indexing engine powers instant as-you-type search across millions of files, letting you filter results by file size, folder size, media type, or modification date in milliseconds. Rich media thumbnails render automatically for videos, office documents, audio album artwork, and interactive 3D models, while integrated OnlyOffice support lets you edit spreadsheets and word processing documents directly inside your browser tab. Built-in WebDAV server support allows desktop operating systems and mobile file apps to mount your remote directories as native network drives. Sharing files with external collaborators takes seconds through customizable public or private links with expiration timers, download limits, password protection, anonymous upload permissions, and custom branding themes. Administrators can authenticate users via OpenID Connect, LDAP, JSON Web Tokens, proxy headers, or local passwords with two-factor authentication, then enforce path-level read, write, and delete rules per user or group. Developers and automation engineers can generate long-lived API tokens and explore the interactive Swagger endpoint to script file transfers and directory provisioning. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache-2.0 licensed.