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.
Wikipedia - Wikipedia is a free online encyclopedia, created and edited by volunteers around the world and hosted by the Wikimedia Foundation.
Standard Notes - A safe place for your notes, thoughts, and life's work
Encyclopædia Britannica - Explore the fact-checked online encyclopedia from Encyclopaedia Britannica with hundreds of thousands of objective articles, biographies, videos, and images from experts.
Joplin - 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, tagged and modified either from the applications directly or from your own text editor.
Kiwix - Kiwix enables you to have the whole Wikipedia at hand wherever you go!