Notes on Windows, macOS, Linux, Android, iOS, and the terminal, synced through your own server: Joplin pairs its open-source clients with Joplin Server, the official self-hosted backend that replaces Dropbox, OneDrive, or Nextcloud as the synchronization target. Notes are Markdown with inline attachments (images, PDFs, audio), organized into hierarchical notebooks and sub-notebooks with cross-cutting tags, alongside to-do lists with reminders and alarms. End-to-end encryption is the headline feature: enabled in the clients, it encrypts sync payloads on-device before upload, so the server stores blobs it cannot read - genuine protection even if the host is compromised. The desktop app offers both Rich Text and Markdown editors, extended by a plugin ecosystem, custom themes, and an Extension API for writing your own scripts; a Web Clipper for Chrome and Firefox captures full pages or screenshots straight into notebooks. Joplin Server ships as a Docker image with SQLite for evaluation and PostgreSQL for production, offers a filesystem storage driver for large content, and includes multi-user support and note sharing - all free under AGPL-3.0 when self-hosted. Notes stay in an open format, so the exit path always exists.

A notes app that is deliberately not a second brain: notesd keeps your grocery lists, journals, and work notes on a server you run, and syncs them to your phone for fully offline use. The web app and the native Android and iPhone apps each keep a complete local copy, so you can write on a subway and watch everything merge when a connection returns; conflicting edits are combined, or preserved as a linked conflicted copy instead of silently overwriting. Notes are stored as Markdown, so exporting your data or mirroring it to a folder of .md files is always one command away. Tags typed anywhere in a note, including nested ones like #home/garden, collect automatically in the sidebar, and Spaces keep work, personal, journal, and recipes in separate contexts. Full-text search runs across titles and bodies, indexed and ranked both on the server and on your phone. Individual notes can be locked with AES-256-GCM encryption performed on your device, unlocked by password, passkey, or biometrics, while the server only ever stores ciphertext. A few accounts per server, each with its own database, make it easy to host notes for family or friends. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Papyra gives you a calm, private home for notes that stays as easy as sticky notes while quietly linking everything together like a wiki. Cards pin, colour, and drag into place on your desk, and opening one drops you into an editor where slash commands insert headings, checklists, tables, or maps without leaving the keyboard. Type two brackets to link another note, and backlinks gather the other direction automatically, following the note even if you rename it. Notes save themselves, and every earlier version is kept, so you can scrub back through history and restore the draft you actually wanted. Sharing a note lets several people type in it together with visible cursors, comments in threads, and mentions that bring the right person in. Private notes lock behind a PIN or your fingerprint and sit encrypted on disk, while a daily journal page collects the day with a mood and a calendar to browse the year. Search covers notes, to-dos, and attachments with highlighted matches, and image text and audio transcripts can join the index. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.

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.

The entire wiki - content, code, and interface - is built from "tiddlers," small addressable units of information that link, transclude, tag, and filter into each other: TiddlyWiki is a non-linear personal notebook with a design philosophy unlike anything else in this catalog. Instead of pages in a hierarchy, you compose views by pulling tiddlers together on demand, which is why researchers, zettelkasten practitioners, and GTD devotees have sworn by it for two decades. The whole application is JavaScript, and the UI itself is written in hackable WikiText - customization goes as deep as rewriting the interface from inside the wiki. Self-hosting runs the Node.js version, which upgrades the classic single-HTML-file architecture in the ways that matter for a server: every tiddler is stored as an individual text file (Git-friendly, organizable), edits save through the HTTP API from any modern browser including phones, and one installation can serve multiple wikis blending shared and unique content. The plugin ecosystem covers graph visualizations, themes, languages, and hundreds of community extensions, declared per-wiki in a simple tiddlywiki.info file; the newer MultiWikiServer plugin adds multi-user accounts and tiddler sharing. Your notes stay usable for decades, independent of any corporation - the project's founding promise. BSD-licensed.

For people whose notes number in the tens of thousands, Trilium Notes is the hierarchical note-taking application built specifically for large personal knowledge bases - actively maintained as TriliumNext. Notes arrange into arbitrarily deep trees where every note is both content and container, and cloning lets a single note live in multiple places at once - bash notes belong under both Linux and Scripting, and Trilium refuses to make you choose. A WYSIWYG editor handles rich text, tables, math, and syntax-highlighted code blocks with Markdown-style shortcuts, while dedicated note types cover Excalidraw sketches, mind maps, geo maps with GPX tracks, relation maps that visualize connections between notes, and tables with typed columns. The attribute system is the power layer: labels attach queryable metadata (#year=1999, #author), relations create named links between notes, and both inherit down the tree - feeding full-text search, saved queries, and scripting. Scripting is Trilium's deepest differentiator: JavaScript code notes run on events like note changes or hourly schedules, build custom widgets, and add server-side logic, turning the knowledge base into a programmable platform. Protected notes encrypt sensitive content, note hoisting focuses on subtrees, and the self-hosted server syncs desktop clients across devices.

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.

With over 75,000 GitHub stars and native apps across macOS, Windows, Linux, iOS, and Android, AppFlowy is the most widely adopted open-source alternative to Notion — delivering the same block-based workspace model with full data sovereignty. The Flutter frontend renders natively on every platform while a Rust backend powered by Actix-web and Tokio handles CRDT-based real-time collaboration, ensuring sub-second sync across devices with conflict-free concurrent editing. Relational databases support grid, board, kanban, calendar, and gallery views over the same dataset, with two-way relations, rollups, advanced filters, sorts, and formula calculations that cover the majority of Notion's database workflows. The block editor supports 40+ content types including nested pages, toggles, callouts, code blocks with syntax highlighting, embeds, and slash-command insertion. AI integration connects to OpenAI, Anthropic, or local models via Ollama for writing assistance, summarization, and translation — all without sending data off-premises when using on-prem LLMs. Team spaces with workspace-level and per-page permissions, OAuth and SSO authentication through GoTrue, and S3-compatible object storage via MinIO provide enterprise-grade access control and file management. The self-hosted stack deploys through Docker Compose with PostgreSQL for metadata, Redis for caching and pub/sub, and a dedicated background worker for imports and email notifications. Offline-first architecture ensures the desktop app functions without connectivity, syncing changes when the connection resumes. 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.

Standard Notes keeps your notes, files, and tags encrypted on your device before anything touches the network, meaning the server stores only ciphertext it cannot read. Cross-platform sync across desktop, mobile, and web delivers fast, conflict-free updates on unlimited devices with the same zero-knowledge guarantee that only your password can decrypt your content. The V2 server architecture condenses everything into four Docker containers consuming roughly 570MB RAM total (down from 13 containers and 1.7GB in the legacy setup), with startup under one minute. Revision history automatically preserves every version of every note, so recovering deleted text or reverting to a previous state never depends on manual backups. A nested tag system organizes thousands of notes with hierarchical categorization that goes well beyond flat folder structures, while search operates entirely on client-side decrypted content. File attachments of any type encrypt and sync alongside notes with identical end-to-end protection. Multiple editor options span plain text, Markdown with preview, and rich formatting to fit different writing workflows. Two-factor authentication via TOTP with email backup codes adds a second barrier beyond your password. An optional separate container serves the web frontend, providing browser access to your encrypted vault without depending on standardnotes.com infrastructure. With 5,500+ GitHub stars and active development, the project continues expanding editor plugins and sync improvements.

Every line an indentable bullet, every bullet a first-class block that can be referenced, embedded, and queried anywhere: Logseq is a privacy-first, local-first knowledge platform built around the block outliner. The daily journal is the system's beating heart - each day opens a fresh date-stamped page where tasks, meeting notes, and fleeting ideas land as blocks without filing decisions, then connect later through [[wikilinks]] with automatic bidirectional backlinks and ((block references)) that transclude any bullet into any page. Everything persists as plain Markdown or Org-mode files on disk - git-friendly, greppable, and owned forever, with sync via iCloud, Dropbox, Syncthing, Git, or an optional end-to-end encrypted service. Built-in tooling goes beyond notes: TODO/DOING task states with scheduling, native PDF annotation with area highlights, spaced-repetition flashcards, whiteboards for visual thinking, Zotero integration for researchers, and Datalog-powered queries that build dynamic views across the entire graph. A marketplace of hundreds of community plugins and themes adds AI chat, Ollama local-model integration, and custom workflows. Written in Clojure/ClojureScript, AGPL-3.0 licensed with 320+ contributors, and completely free - the local-first Roam for people who refuse subscriptions and lock-in.

Open the page, write a Markdown note, move on - Memos is a lightweight, self-hosted service built for quick capture. Instead of folders, notebooks, and titles, it presents a timeline: open the page, write a Markdown note, and move on. Notes support headings, code blocks with syntax highlighting, task lists, tables, and file attachments, with tags auto-extracted from #hashtags in the text. Each memo carries a visibility level, private, protected (logged-in users), or public, so one instance works as a personal log, a small team wiki, or a lightweight microblog. The backend is a single Go binary with a React frontend, around 50 MB of memory at runtime and a ~20 MB Docker image, so it fits comfortably on the smallest instance size with near-zero maintenance. SQLite is the default store, with MySQL and PostgreSQL supported for multi-user deployments needing more concurrency, and full REST and gRPC APIs - Connect RPC for browsers, gRPC-Gateway for external tools - make capture scriptable from CLIs, bots, and automation platforms. Fast full-text search spans all memos, pinned notes keep references handy, and a masonry view suits visual browsing. MIT-licensed with zero telemetry; content is stored as plain Markdown in a database you control, so notes remain readable, exportable, and free of proprietary formats.

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.

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.

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.

A web interface for a folder of Markdown files - Flatnotes is exactly that, and the discipline of that design is why people love it. Every note is a plain .md file in a single flat directory: no database, no proprietary format, no hierarchy to maintain, no export step if you ever leave. Edit notes in the browser or open the same files in VS Code or Obsidian, sync them with Syncthing or rsync while the app is running - the Whoosh-powered search index synchronizes incrementally, so external edits just show up. The interface is a clean Vue.js app with both WYSIWYG and raw Markdown editing modes (TOAST UI Editor), instant full-text search behind the "/" shortcut with partial-match support, wikilinks for cross-note references, and automatic tag extraction from #hashtags in note bodies. Light and dark themes and a mobile-responsive layout make it pleasant everywhere. Authentication is flexible for a personal tool: none, read-only, username/password, or TOTP two-factor. A documented REST API covers create/read/update/delete for automation. The operational story is the quiet selling point - the only state is the notes folder and a rebuildable index, so backup is copying a directory. For a personal notepad that respects your data, Flatnotes nails minimal.

Poznote serves as an all-in-one personal knowledge base and digital workspace designed to bridge unstructured thinking and structured documentation. The platform pairs a responsive Markdown editor with live side-by-side rendering, KaTeX mathematical notation, and interactive Mermaid diagram compilation. Creative thinkers can switch instantly to an embedded Excalidraw infinite canvas to sketch system architectures, design mind maps, and create interface wireframes alongside their written notes. Every directory within the workspace can be toggled into an agile Kanban board where nested folders become customizable workflow columns and notes transform into draggable task cards. Task management views aggregate checklists across documents into unified priority queues with due date reminders and completion filters. An integrated bi-directional Git synchronization engine connects user workspaces directly to personal GitHub or Forgejo repositories, versioning edits automatically on save. The software also provides an integrated Model Context Protocol server that enables AI coding assistants to search notes, create documents, and query knowledge repositories securely. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

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.

Notes are personal, and Plainpad keeps them that way by running entirely on your own server instead of a vendor cloud. Class notes, trip plans, lyrics, and side-project ideas sit in one fast list that searches instantly and opens in any modern browser, adapting to phones, tablets, and desktops. Added to a home screen it launches like an app, and offline editing keeps writing possible when the connection drops. Turning on encryption stores titles and content encrypted at rest, so even database access does not expose what you wrote. One installation supports unlimited accounts with administrator and user roles, and every person keeps a private notebook no one else can read. There are no note limits, no device limits, no ads, and no tracking of any kind. Moving in is scripted through the built-in REST API, which can import collections from files and other note services into the right accounts. The stack asks only for PHP and MySQL, or a single Docker Compose command, and a sample data seeder can populate a fresh install with realistic study notes for evaluation. Simplicity is the design goal: the interface stays quiet, loads quickly, and leaves the words in front. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL 3.0 licensed.

Anchor is a self-hosted note-taking app that keeps every note on your own server and on your devices, so your ideas stay searchable and editable even with no connection at all. Open the web app or the phone app and start typing; the rich text editor handles headings, checklists, highlights, and formatting from a slash menu, and everything saves locally first. When a connection comes back, changes sync automatically across your devices, so the thought you captured on a train is waiting on your desk. Organize with colored tags, pin the notes you live in, archive the ones you are done with, and set one-time or repeating reminders so a note resurfaces when it matters. Notes can carry image and audio attachments, custom backgrounds, and a full version history you can roll back. Share a note with another user as view-only or editable, search titles and body text across everything including the archive, and recover deleted notes from the trash during the recovery window. Bring an existing library with you through Markdown import, a full Anchor backup, or a Google Keep export, and take everything out again the same way. An admin panel controls registration and shows system statistics, and OpenID Connect sign-in through providers like Authelia or Keycloak can replace local passwords entirely. 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.