HelpNDoc - What is HelpNDoc ? Easy to use yet powerful help authoring environment which can generate various documentation formats from a single source.
MadCap Flare - Documentation for Any Audience, Language or Format
Dr.Explain - Dr.Explain software is a help file authoring tool.
ClickHelp - Create, translate, and publish technical documentation easily in one portal, anywhere in the world!
CHM Editor - Best solution to edit CHM files
Adobe RoboHelp - Adobe RoboHelp empowers organizations to deliver engaging help and policy content across mobile devices, formats, and platforms.