Fess

Fess is a self‑hostable enterprise search server that runs on any system with a Java runtime or Docker. It bundles a full‑text search engine based on OpenSearch, an administration GUI accessible through a browser, and a built‑in crawler capable of indexing content from web servers, file systems, and various data stores such as CSV files, databases, and cloud services. The server supports a wide range of document formats, including Microsoft Office, PDF, and zip archives, and offers features like secure authentication, single sign‑on, faceted navigation, and responsive web design.

The software is targeted at organizations that need to provide searchable access to internal documents, code repositories, or website content without relying on external services. Administrators can configure crawling targets, edit search screens, and manage dictionaries directly from the admin UI, while developers can extend functionality through plugins, scripts, and JSON‑formatted integration points.

Fess is distributed under the Apache‑2.0 license, available as free‑tier, open‑source software with no subscription requirement. It can be installed via downloadable packages (deb, rpm, zip) or through provided Docker images and compose files, offering a quick start and a stable, production‑ready platform for enterprise search use cases.