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.

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.

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.

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.

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.

TriliumNext organizes notes in an infinitely deep tree where any single note can be cloned into multiple branches without duplication, building personal knowledge bases that mirror how ideas actually connect rather than forcing a single rigid folder hierarchy. Carrying forward the original Trilium project under active community stewardship with nearly 37,000 GitHub stars, the application is built on TypeScript with a CKEditor 5 WYSIWYG editor supporting rich text, tables, images, KaTeX math expressions, Mermaid diagrams, Excalidraw canvases, mind maps, spreadsheets with XLSX and CSV import/export, and code blocks with full syntax highlighting. A built-in JavaScript scripting engine runs on both frontend and backend, enabling custom widgets, automated workflows, scheduled tasks, and direct interaction with external REST services through a typed Script API. Full-text and fuzzy search with attribute-based queries locates any note instantly across databases tested at over 100,000 notes without performance degradation. The v0.104 release introduced importers for OneNote, Notion, Google Keep, Anytype, and Obsidian alongside 16 dedicated security fixes. Per-note AES encryption, OpenID Connect authentication, and TOTP two-factor protection safeguard sensitive content. The sync server keeps desktop clients, the progressive web app, and mobile devices in lockstep with zero third-party cloud dependency. Web Clipper captures content directly from browsers. 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.

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.

Sage Wiki turns a pile of unstructured documents into a fully interlinked, searchable wiki by running them through a five-pass LLM compiler pipeline. Inspired by Andrej Karpathy's vision of LLM-compiled knowledge bases, the pipeline processes source files through diff detection, summarization, concept extraction, image captioning, and cross-reference discovery, with parallel LLM calls and checkpoint/resume for vaults scaling to 100,000+ documents. The typed ontology graph stores entities and relations with BFS traversal, configurable relation types, multilingual synonyms, and a promotion/demotion lifecycle backed by grounding verification and consensus scoring. Multi-format ingestion handles Markdown, PDF, Word, Excel, PowerPoint, EPUB, email, CSV, images, and code files without manual tagging. LLM provider support spans Anthropic, OpenAI, Gemini, Ollama, and any OpenAI-compatible API, with per-pass model routing enabling cost optimization by assigning cheaper models to simpler tasks. The built-in MCP server exposes 17 tools over SSE transport for integration with Claude, Cursor, and any MCP-compatible agent, while native Obsidian vault overlay ensures existing note workflows remain undisrupted. Team deployment supports Git-synced shared wikis, centralized server access, and hub federation across multiple projects. Ships as a single Go binary with Docker Compose multi-arch images serving the web UI on port 3333. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

"Somewhat lightweight, low-friction" is how Silicon Notes' author describes the personal knowledge base - written after DokuWiki's editor "drove me mad" and no existing wiki quite fit. The philosophy is that small frequent annoyances compound into cognitive load with no return, so everything here is optimized for frictionless daily use. Notes are written in plaintext Markdown and rendered as clean HTML with Pygments syntax highlighting for code blocks; pages get bi-directional relationships (backlinks), so the knowledge base becomes a connected web rather than a folder tree; and full-text plus title search retrieves anything fast. A table of contents lives in the left sidebar - "where it belongs" - editable while you read without scrolling away. Page history tracks revisions for auditing and rollback, JSON export/import keeps everything portable, and the mobile layout is genuinely usable. The stack is deliberately minimal: Python and Flask with Mistune for Markdown and SQLite for storage - no big frameworks, just a few small dependencies. One honest caveat: there is no built-in authentication, so deploy it behind a VPN, private network, or reverse-proxy auth layer. For a solo engineer's brain, it is exactly enough.

PenX delivers an open-source structured note-taking application that functions as a personal database disguised as an elegant editor — combining the outline workflow of Workflowy and Roam Research with the structured data capabilities of Tana through MetaTags that transform every note into a queryable database record. The local-first architecture stores all data on-device using PGLite, an in-process PostgreSQL-compatible engine, ensuring data ownership regardless of cloud connectivity. End-to-end encryption protects all synchronized data so that even the sync server cannot read your notes, tasks, ideas, or documents. GitHub-based version control provides out-of-the-box backup and history with full commit-level recovery. MetaTags are the core innovation — attaching structured tags to any note converts it into a database entry with typed fields, enabling table views, filters, and queries across your knowledge base without imposing rigid folder hierarchies. The daily notes workflow encourages free-form capture while MetaTags handle organization automatically, letting you record thoughts without deciding physical location upfront. AI-driven features assist with content generation, summarization, and intelligent search across your personal data hub. Real-time sync keeps web, desktop, and mobile in perfect alignment. Cross-platform availability includes web, desktop for Windows, macOS, and Linux, iOS, and Chrome extension. Deploy the web service via Next.js with pnpm using tRPC and Prisma. 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.