Fess

Fess is an open-source enterprise search server that crawls websites, file systems, and data stores for full text indexing. It provides a centralized search interface to locate documents across diverse storage locations and formats, consolidating fragmented information into a single searchable index. The software is deployed as a server application and requires a Java runtime environment to operate on various platforms.

Users manage the system through a browser-based administration interface where they register crawling targets and schedule indexing tasks. It can be installed via ZIP, DEB, or RPM packages, or deployed using Docker images that bundle the necessary backend components for quicker setup. The system also includes a search UI that can be embedded into existing websites to provide site-specific search functionality.

Key features

• Full-text search with faceting, sorting, and search suggestions
• Crawlers for websites, file systems, databases, cloud storage, and SaaS
• Support for PDF, Microsoft Office, and ZIP archive formats
• Browser-based administration UI and a REST API
• Role- and permission-based filtering of search results
• Single sign-on integration with LDAP, OpenID Connect, SAML, SPNEGO, and Microsoft Entra ID
• Multilingual user interface and text analysis for over 20 languages
• Extensibility via data store, ingest, script, and theme plugins

Fess is built on OpenSearch, which serves as the search engine backend for indexing and retrieval. The architecture allows for significant customization through a plugin system, enabling the addition of new data store connectors, ingest scripts, and visual themes. It is designed for organizations that need to index large volumes of unstructured data across multiple platforms while maintaining strict access controls through its permission-based filtering, ensuring users only see results they are authorized to access.

This software serves as a self-hosted solution for full-text indexing and information retrieval in enterprise environments.