Manuskript - Open-source tool for writers.
Calmly Writer - Distraction-free text editor for Mac, Windows, Linux and ChromeOS.
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.
Writebox - Writebox is a simple and distraction-free text editor for Chrome and iPhone/iPad.
Novelize - Novelize is an online novel writing app designed to keep authors on track.
Stashany - Online notepad for developers