Software as a service (SaaS) services featuring software for securely collecting, organizing, storing, indexing, retrieving, and managing digital content, documents, data sources, and metadata; providing temporary use of online non-downloadable software for metadata extraction, document classification, semantic search, tracking information provenance and document versions, managing user access permissions, and creating knowledge graphs linking documents, sources, claims, and citations; providing temporary use of online non-downloadable software for artificial intelligence-assisted research, document analysis, and retrieval of stored information to support generation of responses by artificial intelligence systems; providing temporary use of online non-downloadable software for integrating content repositories and information retrieval functions into third-party applications through application programming interfaces (APIs).