NotePlan

Anytype is a local-first, end-to-end encrypted workspace for notes, docs and databases. It lets people build a personal knowledge base from linked objects without relying on the cloud.

Logseq is a privacy-first, open-source outliner for organizing notes and tasks. It links ideas through bidirectional references and daily journals, storing everything as local Markdown files.

Heptabase is a visual note-taking tool that places notes on infinite whiteboards. It helps students and researchers connect ideas, organize sources and make sense of complex topics.

Capacities is an object-based personal knowledge management and note-taking app where everything is a typed, linked object rather than a file in a folder. It is designed to help you connect ideas with daily notes, backlinks, and a graph of your knowledge.