GitHub + Slack Integration - Full visibility into your GitHub projects right inside Slack
Dr.Explain - Dr.Explain software is a help file authoring tool.
Stack Overflow Documentation - A crowdsourced developer documentation
HelpSmith - HelpSmith is a help authoring tool to create CHM HTML help files, manuals, and PDF documents.
ask-stack - Get answers from Stack Overflow directly in the Atom editor
MadCap Flare - Documentation for Any Audience, Language or Format