Novelize - Novelize is an online novel writing app designed to keep authors on track.
MediaWiki - MediaWiki is a free software wiki package written in PHP, originally for use on Wikipedia.
StoryMill - Developers and publishers of Mac, Win, and iOS productivity, home and office and writing software such as MacGourmet, Paperless and many more. Based in MN.
TiddlyWiki - a non-linear personal web notebook
Manuskript - Open-source tool for writers.
Confluence - Confluence is content collaboration software that changes how modern teams work