Trilium Notes

Trilium Notes (TriliumNext) is an open-source, self-hosted hierarchical note-taking application for building large personal knowledge bases. It stores notes in a tree structure with rich text, code notes, and relations, all backed by a single local data directory (no external database). First run: open the app and complete the setup wizard to set your password. Data persists to /home/node/trilium-data. Source: GitHub