Evernote – Our note taking app helps you capture and prioritize ideas, projects and to-do lists, so nothing falls through the cracks. Start your free trial today!
WikidPad – wiki notebook for Windows/Linux/Mac OS.
The Guide is an application that allows you create documents (“guides”) which inherently have a tree (which you can modify as you please) and text associated with each node of the tree. The text itself is of the rich-text variety, and the editor allows you to modify the style and formatting of the text (fonts,... [Read the full review]
RoamResearch.com – A note taking tool for networked thought. As easy to use as a word document or bulleted list, and as powerful for finding, collecting, and connecting related ideas as a graph database. Collaborate with others in real time, or store all your data locally.
Nimbus Note – Transform information chaos from multiple sources into an organized workplace. Empower yourself or your team to get things done faster with less iterations, and fewer meetings.
Simplenote – The simplest way to keep notes. Light, clean, and free. Now available for iOS, Android, Mac, and the web.
Obsidian – A knowledge base that works on local Markdown files.
Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, can be copied, tagged and modified either from the applications directly or from your own text editor. The notes are in Markdown format.