Markdown Guide
Documentação
Choose an open source license
BookStack
DevDocs API Documentation
DocFX - static documentation generator | DocFX website
GitBook
Headway - Keep customers in the loop about your product.
HelpNDoc Help Authoring Tool - Create Help Files, User Manuals and eBooks | HelpNDoc
MkDocs
OverAPI.com | Collecting all the cheat sheets
Read the Docs
ReadMe