LibreOffice - Writer - Open-source cross-platform word processor.
OmPad - OmPad is a free, simple, powerful, beautiful and minimal writing app that helps you focus and...
Microsoft Word - Microsoft Word is a commercial word document processor for Windows.
Scribes - A text editor for GNOME that combines simplicity with power.
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.
Caret - Better Markdown Editor for Mac / Windows / Linux