Dr.Explain - Dr.Explain software is a help file authoring tool.
WinCHM - Creating CHM file, Make CHM file, Web Help. WinCHM Pro - Help authoring software (CHM, WebHelp, DOC, PDF) . With this powerful tool you can not only create chm file from scratch, but also convert a set of existing HTML files to a chm file.
MadCap Flare - Documentation for Any Audience, Language or Format
Document360 - Self-service knowledge base software focused on SaaS Products & Enterprise Software Projects.
ClickHelp - Create, translate, and publish technical documentation easily in one portal, anywhere in the world!
HelpSmith - HelpSmith is a help authoring tool to create CHM HTML help files, manuals, and PDF documents.