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.

Alexandrie provides a structured knowledge base with an extended Markdown editor, granular per-document permissions, and offline editing through its progressive web app. The CodeMirror 6 editor goes well beyond standard Markdown with colored containers, academic callout blocks, KaTeX math expressions, syntax-highlighted code blocks, footnotes, interactive checkboxes, cards, panels, and a custom snippet system with import and export. Full-text search via the Ctrl+K command center returns instant results with content snippets and relevance ranking across all workspaces. Five permission levels covering None, Read, Write, Admin, and Owner apply per document and per user, while OIDC single sign-on integrates with Google, GitHub, Microsoft, Discord, and any OpenID Connect provider. Documents organize into a hierarchical tree of workspaces, categories, and nested entries with tags, bookmarks, pinned notes, and custom icons. Integrated Kanban boards handle task management within each workspace without switching applications. The PWA installs on any device for full offline editing with seamless sync when connectivity returns. Voice-to-text dictation captures notes hands-free, and one-click ZIP backup exports all documents, files, and settings as a portable archive. Over 2,000 GitHub stars and 41 releases back the project. The Docker Compose stack orchestrates the Nuxt 4 frontend, Go Gin backend, MySQL 8 database, and S3-compatible RustFS object storage. Running on a VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Confluence and Notion both want your team's documentation in their cloud; Docmost, an open-source collaborative wiki platform, keeps it on your server. The centerpiece is a Notion-style block editor with CRDT-based real-time collaboration: multiple people edit the same page simultaneously and changes merge without conflicts or overwrites. Content lives in spaces - per team, project, or department - with nested page trees, role-based permissions, groups, inline comments, page history with restore, and full-text search across everything. The editor covers tables, code blocks, callouts, KaTeX math, and file attachments, and diagramming is built in rather than bolted on: Mermaid, Draw.io, and Excalidraw all render inside pages, alongside embeds for Airtable, Loom, Miro, and more. Migration paths include Notion, Markdown, HTML, and ZIP archive imports (Confluence, PDF, and DOCX importers ship in the Enterprise edition, along with SSO via SAML/OIDC/LDAP and MFA). The stack is TypeScript with PostgreSQL and Redis, deploys via Docker Compose, runs in air-gapped environments with no external dependencies, and is translated into 10+ languages. The AGPL-3.0 community edition carries no per-seat fees; the project has passed 20,000 GitHub stars since its 2024 launch.

With a deliberately minimalist design philosophy and zero database dependencies, DumbPad delivers a self-hosted notepad that stores notes as plain text files with real-time auto-saving every 10 seconds and keyboard-shortcut manual saves. The Node.js Express backend serves a vanilla JavaScript frontend that supports multiple named notepads with direct URL linking and shareable links for instant access to specific notes. The split-view editor displays markdown source on the left and rendered preview on the right with a draggable resize handle, while the full preview mode renders complete markdown with GitHub-style alert blocks for Note, Tip, Important, Warning, and Caution callouts, extended table formatting, fenced code blocks with syntax highlighting via highlight.js covering approximately 180 programming languages, collapsible details sections, and checklist support. Fuzzy search matches across both filenames and file contents for fast navigation across large collections. Optional PIN protection secures access with configurable 4 to 10 digit codes, constant-time comparison to prevent timing attacks, brute force lockout after 5 failed attempts with 15-minute cooldown, and IP-based tracking. The Docker container runs as non-root UID 1000 by default with multi-architecture support, CORS origin restrictions for reverse proxy deployments, and persistent data volumes. Notes can be downloaded as text or markdown files, printed with auto-expanded collapsible sections, and imported by placing text files directly into the data directory. On RepoCloud, deploy DumbPad on a dedicated VPS with Docker, root SSH access, and complete control over your note-taking infrastructure, all under the GPL-3.0 license.

Team and product documentation on a fast Vue frontend with PostgreSQL storage: Wiki.js is a Node.js wiki engine. Its distinguishing trait is per-page editor choice: authors pick Markdown with live preview, a WYSIWYG visual builder for non-technical writers, or raw HTML, page by page. Native Git synchronization commits every page change to GitHub, GitLab, Bitbucket, Azure DevOps, or any Git remote - bi-directionally, so edits made in the repository flow back into the wiki - giving documentation version-controlled backup for free. Authentication coverage is among the broadest of any self-hosted wiki: local accounts with self-registration, social login via Google, GitHub, Discord, and Slack, and enterprise SSO through LDAP/Active Directory, SAML, CAS, Auth0, Okta, Azure AD, Keycloak, and generic OAuth2/OIDC, with optional MFA. Built-in full-text search runs on PostgreSQL with zero setup, and external engines like Algolia or Solr can substitute. Page history with visual version comparison, granular group-based permissions per path, nested navigation menus, 50+ integration modules, and full localization round it out. AGPLv3-licensed with a 28k-star community.

Most wikis die of flat page-and-tag sprawl; BookStack's defining decision is enforced structure - an MIT-licensed PHP/Laravel platform (over MySQL) where content lives in a hierarchy of shelves, books, chapters, and pages, the way a physical library works. A shelf maps to a department, a book to "Engineering Runbooks," a chapter to "Database Procedures," a page to the actual document. That opinionation removes the "where does this go?" friction and keeps knowledge bases tidy as they grow. Editing works both ways: a clean WYSIWYG editor for most users, a Markdown editor with live preview for those who prefer it - switchable per page. Full-text search spans all books or scopes to one, with direct links to individual paragraphs, and include tags let you embed one page's content inside another so shared blocks update everywhere at once. Every edit creates a diffable, revertible revision. Page templates standardize recurring formats, tags add cross-cutting categorization, and built-in diagrams.net integration draws architecture diagrams in place. Authentication covers email/password plus OIDC, SAML2, LDAP, and social login; a full role and permission system locks content down per shelf, book, or page. Pages and books export to PDF, HTML, plain text, and Markdown, a REST API automates content, and the whole thing runs happily on the cheapest VPS you can find.

Enterprise documentation discipline without enterprise infrastructure: Documize Community is the Confluence alternative built on exactly that trade. The entire platform - Go backend, Ember.js frontend - compiles to a single executable binary for Linux, Windows, and macOS with zero runtime dependencies: no Elasticsearch, no Redis, no JVM. Point it at PostgreSQL, MySQL, MariaDB, Percona, or Microsoft SQL Server (rare in open source, decisive in Microsoft shops), and schema migrations run on launch with native full-text search on whichever engine you chose. Content organization rejects nested-folder sprawl for Spaces, categories, and labels, and the section-based composable editor mixes rich text, Markdown, code blocks, PDFs, diagrams, and embedded Jira or Trello content in one document, with reusable blocks and templates so teams start from standards rather than blank pages. It deliberately unifies internal team docs and customer-facing documentation in one system with granular space-, document-, and action-level permissions deciding who sees what. Where wikis stop, Documize continues: content approval workflows (draft, review, approve, publish), version management, lifecycle control, feedback capture, PDF export, analytics showing what gets read and ignored, activity streams, and audit logs. Keycloak, LDAP, and SSO integrate for enterprise auth. AGPL-licensed.

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.

salt.md is an open-source, self-hosted workspace where your team and its AI agents work on the same documents and databases, under the same permissions and with the same history. A slash-menu block editor handles checklists, tables, callouts, columns, code, diagrams, and embeds. Page links, backlinks, and a graph view show how pages connect. Any page can become a collection with typed properties like select, date, person, relation, rollup, and formula, shown as a table, board, list, gallery, calendar, timeline, or form. Ctrl+K searches titles, body text, row values, and the text inside uploaded PDFs. Two people can type in the same paragraph at once with live cursors. Comments, page history, and an activity log record who changed what. Publish a page as a read-only link with an optional password and expiry, or hand people without accounts a form that adds rows to a collection. Agents connect over MCP with 33 tools for searching, writing, building databases, and commenting, using tokens scoped to one workspace or read-only. Signed webhooks, iCalendar feeds, and Google or Microsoft sign-in link it to the rest of your stack. Import Markdown, ZIP archives, or a Notion export, and export pages as Markdown, HTML, or PDF. Use it for handbooks, meeting notes, project boards, and a knowledge base your assistants can read. 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.

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.

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.

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.

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.

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.

Backed by over 45,000 GitHub stars and described as the tool that replaces Notion, Evernote, and Anki in a single Docker container, SiYuan is the privacy-first knowledge management system where every paragraph, heading, and list item is a uniquely addressable content block. The block-level architecture enables bidirectional links, transclusion embeds, and SQL query blocks that dynamically aggregate content across your entire workspace, while the knowledge graph visualization maps relationship networks between documents and blocks. Built-in databases support table views with relation and rollup columns, filter composition, sorting, and template-based calculations for structured data management alongside freeform notes. The FSRS spaced repetition engine turns any content block into a flashcard with scientifically calibrated review scheduling, eliminating the need for separate memorization tools. AI integration connects to OpenAI-compatible APIs for writing assistance, translation, summarization, and Q&A chat, with semantic search using embeddings and reranking for intelligent content retrieval. The Bazaar community marketplace delivers plugins, themes, templates, and widgets through a managed extension system with TypeScript plugin APIs. End-to-end encrypted synchronization works across S3-compatible storage, WebDAV servers, or SiYuan's own cloud service, while Tesseract OCR extracts searchable text from images and the web clipper captures pages from Chrome, Edge, and Firefox. Export targets include Markdown with assets, PDF, Word, and HTML. 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.

Transforming fragmented research notes, daily technical logs, and project documentation into an interconnected knowledge base is what NoteDiscovery delivers for privacy-conscious teams and researchers. Writers compose rich documents using a dual-pane editor that renders MathJax equations, interactive task lists, and dynamic Mermaid sequence diagrams side by side with raw text. The interactive knowledge graph maps semantic relationships across notebooks, allowing researchers to explore backlinks, uncover hidden topical connections, and navigate complex idea webs visually. Team members sketch architecture diagrams and wireframes directly inside note canvases using the integrated drawing tool, saving revisions as embedded image layers without external editors. The platform organizes thoughts through flexible tag hierarchies, nested folder trees, and reusable document templates equipped with automatic date and variable substitutions. Autonomous coding assistants and language models query documentation, create structured meeting summaries, and update project indexes directly through the native Model Context Protocol server. Built-in export tools convert notebook collections into standalone HTML packages, printable documents, or portable Markdown archives for offline archiving. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

With over 2,200 GitHub stars and a philosophy that your notes should be files you own rather than rows in a database, ZenNotes is the keyboard-first Markdown editor that runs as a self-hosted web app backed by a Go server accessible from any browser on your network. Every note is a plain .md file in a vault directory you mount, with zero proprietary lock-in. Modal editing with real Vim motions, leader-key flows, and a command palette keeps your hands on the keyboard through edit, split, and preview modes. The rendering engine handles KaTeX math, Mermaid diagrams, TikZ graphics, and JSXGraph plots directly from Markdown syntax alongside wiki links and callout blocks. A first-party MCP server ships in the box with one-click integration for Claude Desktop and Cursor, letting AI assistants read and write the same Markdown files on disk without sync layers or duplicate copies. The bundled zen CLI provides note creation, search, tagging, task toggling, and piped capture with JSON output for shell scripting. Board views render plain CSV files as Kanban columns. Daily notes, quick capture, archive, and trash round out the vault workflow. The Go backend serves the browser frontend on port 7878 with token-based authentication, configurable browse roots, TLS proxy support, and file permission hardening at 0600/0700 defaults. Deploy via the multi-arch Docker image for linux/amd64 and linux/arm64. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Draw it, write it as code, or hand it to your AI agent: OpenFlowKit is an open-source diagram canvas where the picture and the text behind it are always the same diagram. Drag shapes on the canvas or type a few forgiving lines, and each side regenerates the other as a single undo step. Ten diagram types share that one language: architecture with C4 views and cloud icons, sequence, flowchart, entity-relationship, state, class, mind maps, git graphs, charts, and wireframes. Paste Mermaid, Structurizr, or D2 and it converts into editable shapes, and Copy as Mermaid sends a flowchart or sequence back out for your README. Paste a GitHub repository instead and Map mode draws its architecture for you, with every arrow citing the exact file and line behind it, and a CLI that maps a local checkout for private repos. Connect Claude Code, Cursor, or any MCP client and the agent draws on your live canvas, restyles what is there, and screenshots its own work to check it. A built-in assistant works with your own key from Claude, OpenAI, Gemini, Groq, Mistral, OpenRouter, or a local Ollama, and exports cover PNG, SVG, PDF, JSON, and animated SVG, GIF, MP4, or WebM you can drop into documentation. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.