* BikeOutliner - A rich text outline editor for macOS
Added: 16a18
* TaskPaper - A plain text outline editor for macOS
The Outliner Family of Text Editors is comprised of those text editors which are designed to work with outlines, trees, and other forms of hierarchical text rather than simple lines of ASCII/EBCDIC text.
Outliner Editor Family
AMLPages? - Shareware outliner/note taker for Windows
Code Browser - A folding text editor with outline view
BikeOutliner - A rich text outline editor for macOS
Dockboard - Open source outline editor for authors