Etherpad
In continuous open-source development since 2009, Etherpad is the original really-real-time collaborative editor - used by Wikimedia, governments, EU public-sector institutions, and tens of thousands of self-hosters. Its core idea is visible authorship: every keystroke is attributed with author colors, every revision preserved, and the timeslider lets you scrub through a document's entire history character by character. Multiple people type into the same pad and see each other's changes instantly - it scales to thousands of simultaneous editors per pad. The base install is deliberately lightweight; capability comes from roughly 290 plugins installable from the admin web UI: comments, images, tables, drawing, video chat via WebRTC, math rendering, code highlighting, and authentication via OAuth, LDAP, or OpenID. AI is pointedly a plugin, not a default - you choose the model and infrastructure, or never turn it on. There is no telemetry. For integrators, an HTTP API (with OpenAPI definitions at /api/openapi.json) manages pads, users, and groups for embedding in your own applications, and the ueberDB abstraction layer supports PostgreSQL, MySQL, Redis, MongoDB, and SQLite backends. Full data export is built in, the format is open, it is translated into 105 languages, and it runs on anything from a Raspberry Pi to a server farm. Apache 2.0 licensed, Node.js based.
OnlyOffice
With 6,800 GitHub stars and over a decade of development since its 2014 release, ONLYOFFICE Docs delivers a self-hosted Microsoft Office replacement with pixel-perfect OOXML rendering and real-time collaborative editing supporting both Fast (character-by-character) and Strict (manual save) co-authoring modes. The suite encompasses five full-featured editors — Document Editor for DOCX/ODT/EPUB/HTML, Spreadsheet Editor with 500+ functions and pivot tables, Presentation Editor with animations and transitions, Form Creator for fillable PDF forms with field validation, and PDF Editor for annotation and conversion — all operating within a unified web interface. Format support spans 50+ types including DOCX, XLSX, PPTX, ODT, ODS, ODP, PDF, CSV, RTF, TXT, and Markdown with server-side conversion between any supported pair. The JavaScript plugin API enables extending editor functionality through a marketplace of ready-made plugins for ChatGPT integration, speech-to-text, OCR, Zotero citations, and Thesaurus. Ready-to-use connectors integrate with Nextcloud, ownCloud, Seafile, Moodle, Odoo, Confluence, SharePoint, Alfresco, Liferay, and Chamilo, while WOPI protocol compliance enables integration with any WOPI-compatible platform. JWT authentication secures all API communications between host applications and the document server. Deploy via Docker with a single command or DEB/RPM packages on Ubuntu, Debian, CentOS, or RHEL. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GNU AGPL v3 licensed.
Suite Docs
An open-source alternative to Notion and Google Docs developed jointly by France's DINUM and Germany's ZenDiS that prioritizes data sovereignty, real-time collaboration, and structured knowledge management. The Yjs-powered CRDT engine provides live cursors, presence indicators, and inline comments enabling teams to edit simultaneously without conflicts, while BlockNote.js renders a clean block-based editing experience with rich text formatting, Markdown shortcuts, and drag-and-drop content organization. Hierarchical sub-documents create wiki-style knowledge bases where documentation nests naturally into navigable structures, and a dedicated slide mode transforms any document into a presentation without separate tooling. The document API separates content from metadata with distinct endpoints for formatted content, raw content streams, and document properties. Optional AI integration connects to configurable language models for writing assistance, summarization, and content generation directly within the editor. Access control supports granular permissions per document with team sharing, public links, and invitation flows. DOCX import brings existing documents into the platform while maintaining formatting fidelity. The Django backend serves a REST API with PostgreSQL storage, Redis caching, and S3-compatible media handling. Deploy via Docker Compose, Kubernetes with the official Helm chart, Nix, or YunoHost on your own infrastructure. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
EdenText
EdenText is a full word processor, from quick notes to full-length books, that opens the docx and odt files you already have and keeps them looking the way Word or LibreOffice made them. Pages are real pages: A4 or Letter sizes, margins, headers and footers, footnotes, columns, and watermarks, with mirrored margins and chapters opening on the right-hand page when you are laying out a book. Paragraph, character, table, and list styles cascade with inheritance and chapter numbering, and tables sort rows and compute spreadsheet-style formulas. The academic toolbox is complete: table of contents, captions, cross-references, citations with bibliography, an alphabetical index, and LaTeX formulas. Reviewing works the way editors expect, with tracked changes, threaded comments in margin balloons, printable markup, spell checking in eight languages, and grammar checking for English. An optional AI assistant answers questions about the document and proposes edits as tracked changes through your own model provider. Nothing waits on a server: documents autosave in the browser, the app installs and works offline, and your words never leave the machine. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.
Cryptpad
End-to-end encrypted by design, CryptPad is a real-time office suite where teams write documents, plan on kanban boards, collect answers with forms, and draw diagrams without the hosting server ever seeing their content. Rich text pages come with comments, replies, @mentions, and a document outline, while the Markdown editor adds a live preview, Mermaid diagrams, mind maps, and math. Kanban columns hold colored, tagged cards with Markdown bodies, and the diagram editor exports PNG, JPG, SVG, or PDF. Optional ONLYOFFICE editors add spreadsheets, word-processing documents, and presentations that several people can edit together. The form builder offers text, choice, grid, date, ranking, and poll questions, conditional sections, and separate author, auditor, and participant roles. Documents can be shared with contacts or teams, by link, or as embed code, with view, edit, present, or view-once access. Passwords, expiry dates, owner lists, and access lists limit who gets in, and every edit lands in a history you can step through, restore, or pin as a named snapshot. CryptDrive keeps files in folders, tags, templates, and a trash bin, while teams get their own drive, chat, and member roles. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.
Collabora Office
Real LibreOffice document engineering in the browser: Collabora Online is built by the company employing much of the former SUSE LibreOffice team - not a reimplementation. This deployment runs CODE (Collabora Online Development Edition), the collabora/code server that renders and edits documents entirely server-side while browsers get high-fidelity WYSIWYG output, so layout and formatting survive round-trips that break lesser converters. Four editors ship in one container: Writer for text documents (comments, track changes with comparison and restoration, form handling), Calc for spreadsheets (advanced formulas, macros, pivot tables, per-user sheet views, server-enforced cell protection), Impress for presentations, and Draw for Visio-class diagrams. Format compatibility spans DOCX, XLSX, PPTX, the ODF family, PDF, and dozens more - including Visio and Publisher import. Real-time collaborative editing supports multiple simultaneous editors with visible cursors and commenting. The architectural point: documents are processed on your server and never leave it, which is why Collabora is the engine behind Nextcloud Office and integrates with ownCloud, Seafile, and any WOPI-speaking host - or embeds in your own application via the SDK. An admin console monitors sessions and memory. For organizations that need Google Docs-style collaboration with actual data sovereignty, this is the reference open-source answer.
Doca
Doca puts rich text, Markdown, spreadsheets, slides, and an infinite canvas under one login and one permission model, giving individuals and small teams a self-hosted workspace for writing together. Every format supports real-time co-editing with presence, comments, saved history, and manual snapshots, and rich text and Markdown documents can be restored to an earlier version. Documents live in knowledge libraries with tree navigation, invitations, inherited permissions, share links, and trash, while personal files and shared folders sit on local disk or S3-compatible storage. Knowledge books go further: they subscribe to sources, run an editable workflow, keep source evidence, and route results through human review. A personal AI assistant, powered by whichever model you configure, searches authorized documents, reads PDF and Office attachments, edits images, and prepares browser drafts. MCP services let external AI clients such as Codex use those tools under your permissions. Sign in with a password, OIDC, Google, GitHub, WeChat, or QQ, review registrations before they go live, and send webhooks to other systems. A plugin SDK and marketplace add business modules, and a browser extension clips pages into documents. The interface ships in Chinese and English. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
AtomicServer
Documents, tables, files, chat, and video meetings share one workspace in atomic.place, and AtomicServer is the part you host yourself so a team can edit together while the data stays on a machine it controls. Documents are collaborative rich text with comments, icons, and cover images, tables enforce a strict schema with keyboard navigation and copy and paste, and any table can switch to a kanban, calendar, dashboard, or timer view. Templates start an issue tracker, a CRM, a project task list, or a time tracker. Live cursors, typing indicators, and presence avatars show who is working where, group channels carry attachments, replies, and search, and an infinite canvas can be drawn on together. Every write is a signed commit, so a full history is kept. Read and write rights follow the resource hierarchy, and invite links bring people in. Websites are designed in the browser, published in one click, and rolled back to any earlier version. Custom classes and properties come from the Ontology Editor, small apps are plain JavaScript screens over the same data, and AI features work with any model through OpenRouter or a local Ollama and support MCP. Typeahead search suggests results as you type. A REST API answers in JSON-AD, Turtle, or JSON-LD for automation, and export and import commands write and read JSON-AD backups. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
CollabMD
Your team's knowledge already lives in a folder of Markdown files, and CollabMD turns that exact folder into a shared workspace everyone can edit together in the browser, with nothing to migrate and no database swallowing your notes. Point it at an Obsidian vault, a plain docs directory, or a git-backed repository and the filesystem stays the source of truth: files are never moved, renamed, or deleted unless someone does it deliberately in the app. Several people can type in the same document at once with live cursors and presence indicators, follow a collaborator's view while they present, and drop comments anchored to a specific line or text selection instead of scattering feedback across chat threads. Edits made outside the browser, in Obsidian or any text editor, sync back into open documents automatically, so local and remote work never fork. Diagrams are first-class citizens: Mermaid, PlantUML, Structurizr C4 models, Excalidraw canvases, and draw.io files all open and render beside your prose, and a git panel lets you review changes and commit with a message without leaving the tab. Global full-text search, wiki-links with backlinks, team chat, file uploads, and optional password or Google sign-in round out a workspace that respects how your files already live. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
HedgeDoc
Real-time collaborative Markdown behind your own firewall: HedgeDoc (formerly CodiMD, descended from HackMD's open-source edition) keeps team notes on team infrastructure. Share a note's URL and collaborators are editing together instantly - live cursors, changes appearing keystroke by keystroke - in a three-mode interface that toggles between raw Markdown, rendered preview, and side-by-side split. The Markdown dialect is extended where engineers need it: Mermaid, Graphviz, and Vega-Lite diagrams, MathJax for equations, syntax-highlighted code blocks, embedded content, and a presentation mode that turns a note into reveal.js slides with a single YAML header. A dropdown permission system controls each note - freely editable, limited to signed-in users, or locked read-only - and published notes become clean read-only pages for wider distribution. Revisions track every change with the ability to revert to any earlier version. The AGPL-3.0 codebase is light enough to run on a Raspberry Pi and deploys via Docker with PostgreSQL, MySQL, or SQLite. Authentication covers LDAP, SAML, OAuth2, and email. It deliberately stays a focused document editor - no page trees or kanban - and does that one job with excellent keyboard-first ergonomics for meeting notes, RFCs, runbooks, and shared scratchpads.