Ecco Pro - Ecco Pro was a personal information manager software based on an outliner.

OneNote - Get the OneNote app for free on your tablet, phone, and computer, so you can capture your ideas and to-do lists in one place wherever you are. Or try OneNote with Office for free.

OmniOutliner - OmniOutliner is a writing app for collecting information, outlining ideas, adding structure to any sort of writing.

Org mode - Org: an Emacs Mode for Notes, Planning, and Authoring

Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.

Info Select - Info Select is a Personal Information Manager that organizes Internet data, notes, to-do's...