MediaWiki - MediaWiki is a free software wiki package written in PHP, originally for use on Wikipedia.
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.
TiddlyWiki - a non-linear personal web notebook
CherryTree - A hierarchical note taking application, featuring rich text and syntax highlighting, storing data in a single xml or sqlite file.
Confluence - Confluence is content collaboration software that changes how modern teams work
Turtl - The secure, collaborative notebook