Logseq

Logseq is an open-source, privacy-first knowledge management platform that combines note-taking, task management, and PKM (Personal Knowledge Management) in a local-first, outliner-based interface. Founded by Tienson Qin and maintained by the Logseq community, it has over 35,000 stars as of 2026. Unlike cloud-dependent note apps, Logseq stores all data locally as plain Markdown or Org-mode files, enabling full offline access, version control via Git, and complete data ownership. Key features include: block-based outliner architecture (every paragraph is a block that can be nested, referenced, and embedded elsewhere), bidirectional linking (creating wiki-style connections between notes via [[page names]] and #tags), backlinks panel (showing all references to the current page), block references and embeds (transcluding specific blocks from other pages), journal-first workflow (daily pages serve as the primary entry point for capturing thoughts), PDF annotation (highlighting and annotating PDFs with linked notes), whiteboards (spatial canvas for visual thinking with shapes, connectors, and embedded blocks), flashcards with spaced repetition (via the built-in card system), task management with TODO/DOING/DONE keywords and deadlines, query language for filtering and displaying blocks matching criteria, custom CSS themes, plugin system (over 500 community plugins via the marketplace), mobile apps (iOS and Android) with local storage and optional cloud sync, multi-device sync via Git or iCloud, and support for both Markdown and Org-mode syntax.