Open Source Document Management System
A document system's job isn't really storage, it's answering 'which version is current and who approved it' long after the people involved have left, so the audit trail and metadata model matter more than the viewer. The open source options here keep your documents as ordinary files on storage you control, with versioning, tags, and approval history you can query directly, so the trail survives even if you stop using the software.
Logseq
Privacy-first knowledge base for graph notes, Markdown, Org-mode, PDF annotation, and tasks
Paperless-ngx
Self-hosted document management system for scanning, indexing, and archiving paper files
Docmost
Open-source collaborative wiki and documentation software with real-time editing, spaces, and permissions
Zettlr
Markdown publication workbench for researchers, journalists, and writers with citations and Pandoc exports
CKEditor 5
TypeScript rich text editor framework with WYSIWYG editing, plugins, and collaboration support
ONLYOFFICE Docs
Collaborative online office suite for documents, spreadsheets, presentations, forms, PDFs, and diagrams
LibreOffice
Free open source office suite with Writer, Calc, Draw, Impress, and broad document format support
Teedy
Lightweight document management system with OCR, search, and workflow for personal or business use
Docspell
Self-hosted document management system for organizing scanned, emailed, and imported files