What are some alternatives?
Dillinger - joemccann has 95 repositories available. Follow their code on GitHub.
Pastebin.com - Pastebin.com is a website where you can store text for a certain period of time.
StackEdit - Full-featured, open-source Markdown editor based on PageDown, the Markdown library used by Stack Overflow and the other Stack Exchange sites.
PasteFS - paste tool and a digital assets manager to share text, files, pictures and documents of every kind
Bear - Bear is a flexible writing app for crafting notes and prose.
Ghostbin - Ghostbin is an open source paste service.