triliumnext/trilium

Trilium Notes is a free, open-source note-taking application designed for building large personal knowledge bases. Unlike simple note apps, Trilium organizes notes in a hierarchical tree structure where notes can be nested as deeply as you like, and the same note can appear in multiple places in the tree simultaneously. This makes it well suited for people who accumulate thousands of notes over time and need a flexible system for linking ideas together. Notes in Trilium can contain rich formatted text with tables, images, mathematical formulas, and code with syntax highlighting. There are also specialized note types including mind maps, hand-drawn sketches (via Excalidraw integration), relation maps for visualizing connections between notes, and geo maps with location pins. Full-text search and note versioning (keeping a history of every change) are built in. Trilium can be run as a local desktop application using Electron (a technology that packages web apps as desktop programs), or self-hosted on a server and accessed via browser. Notes can be synchronized across devices through a self-hosted sync server, encrypted on a per-note basis for privacy, and selectively published to the public internet. There is also a web clipper browser extension for saving web pages directly into your notes. Someone building a personal wiki, a research database, a journal, or a project knowledge base where notes grow over time and link to each other would use Trilium. The project is written in TypeScript, runs on Electron for desktop use, and can scale comfortably to over 100,000 notes according to the README.