Dozuki - Dozuki is a web-based tool for creating and distributing step-by-step documentation.
HelpNDoc - What is HelpNDoc ? Easy to use yet powerful help authoring environment which can generate various documentation formats from a single source.
Bloomfire - Let Bloomfire help you get organized! Organize your content, build your company knowledge base and help your employees to be more successful.
Dr.Explain - Dr.Explain software is a help file authoring tool.
REWO - REWO is a knowledge documentation and distribution solution, which drastically improves capturing, visualizing and communicating knowledge.
CHM Editor - Best solution to edit CHM files