wikidPad - wikidPad is an application for storing thoughts, ideas, todo lists, contacts, or anything else that user can think of to write down.
MediaWiki - MediaWiki is a free software wiki package written in PHP, originally for use on Wikipedia.
Simplenote - The simplest way to keep notes. Light, clean, and free. Simplenote is now available for iOS, Android, Mac, and the web.
TiddlyWiki - a non-linear personal web notebook
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.
Confluence - Confluence is content collaboration software that changes how modern teams work