DokuWiki - DokuWiki is a simple to use and highly versatile Open Source wiki software that doesn't require a database.
wikidPad - wikidPad is an application for storing thoughts, ideas, todo lists, contacts, or anything else that user can think of to write down.
Wiki.js - An open source, modern and powerful wiki app built on Node.js, Git, and Markdown.
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.
TiddlyWiki - a non-linear personal web notebook
Simplenote - The simplest way to keep notes. Light, clean, and free. Simplenote is now available for iOS, Android, Mac, and the web.