What are some alternatives?
Confluence - Confluence is content collaboration software that changes how modern teams work
TiddlyWiki - TiddlyWiki — a non-linear personal web notebook
GitBook - Modern Publishing, Simply taking your books from ideas to finished, polished books.
Nuclino - Nuclino is a unified real-time workspace for teams that brings all your notes, tasks, and docs together in one place.
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.
MediaWiki - MediaWiki is a free software wiki package written in PHP, originally for use on Wikipedia.