Novelize - Novelize is an online novel writing app designed to keep authors on track.
DokuWiki - DokuWiki is a simple to use and highly versatile Open Source wiki software that doesn't require a database.
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.
Wiki.js - An open source, modern and powerful wiki app built on Node.js, Git, and Markdown.
Manuskript - Open-source tool for writers.
TiddlyWiki - a non-linear personal web notebook