Stonly Knowledge Base - Interactive knowledge bases and help-centers
HelpNDoc - What is HelpNDoc ? Easy to use yet powerful help authoring environment which can generate various documentation formats from a single source.
Free Knowledge Base by Dashly - Optimize your customer support with Knowledge Base by Dashly
Dr.Explain - Dr.Explain software is a help file authoring tool.
Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.
CHM Editor - Best solution to edit CHM files