Salesforce Service Cloud - Service Cloud integrates customer service with social networks and provides a self-service customer portal and knowledge base system.

HelpNDoc - What is HelpNDoc ? Easy to use yet powerful help authoring environment which can generate various documentation formats from a single source.

Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.

Dr.Explain - Dr.Explain software is a help file authoring tool.

Hubspot Service Hub - HubSpot's customer service software makes supporting customers easy. Help your customers on the channels they prefer, while driving efficiency for your team.

MadCap Flare - Documentation for Any Audience, Language or Format