Free & Open-Source Heptabase Alternatives

Visual whiteboard note system.

1. Logseq ↗ FOSSPRIVATE
   Outliner-style note-taking with bidirectional links.
   ●●○Medium · Imports Markdown / plain text
2. Obsidian ↗ PRIVATE
   Markdown-based knowledge graph (free for personal use).
   ●○○Easy · Imports Markdown / plain text
3. AppFlowy ↗ FOSSPRIVATESELF-HOST
   Open-source Notion alternative — local-first.
   ●●○Medium · Imports Markdown / plain text