outliners

not sure

Organon is a tool for novelists and scientific authors.

Outspline is a free and open-source modular outliner whose functionality can be extended with addons. The most important addon is Organism, which adds advanced time management features and turns the application into a personal organizer, perfectly suited for working with todo...

MyTetra is open source and cross platform personal manager for information accumulation. It is powerful program for data memorization and structuring notes.