Bit.ai - Bit is a smart real-time document collaboration platform for teams to create interactive documents, manage digital content and track document insights.
Airborn - Create and edit documents online without sacrificing your privacy
Google Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.
Mellel - Home Page for Mellel: The word processor of choice for scholars, writers and long document writing. for Mac OS X and iOS.
Archbee.io - Archbee is a developer-focused product docs tool for your team. Build beautiful product documentation sites or internal wikis/knowledge bases to get your team and product knowledge in one place.
WordTsar - WordTsar is an open-source word processing software that provides you the basic options to create the document easily.