Pollen - Pollen is a publishing system that helps authors create beautiful and functional web-based books.
LibreOffice - Writer - Open-source cross-platform word processor.
Tectonic typesetting - A modernized, complete, standalone TeX/LaTeX engine.
Microsoft Word - Microsoft Word is a commercial word document processor for Windows.
SILE - SILE is a typesetting system inspired by TeX and InDesign, but seeks to be more flexible...
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.