LibreOffice - Writer - Open-source cross-platform word processor.

Typora - A minimal Markdown reading & writing app.

Microsoft Word - Microsoft Word is a commercial word document processor for Windows.

Dillinger - joemccann has 95 repositories available. Follow their code on GitHub.

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.

StackEdit - Full-featured, open-source Markdown editor based on PageDown, the Markdown library used by Stack Overflow and the other Stack Exchange sites.