MadCap Flare - Documentation for Any Audience, Language or Format
Slite - Your company knowledge
Document360 - Self-service knowledge base software focused on SaaS Products & Enterprise Software Projects.
Docusaurus - Easy to maintain open source documentation websites
Adobe RoboHelp - Adobe RoboHelp empowers organizations to deliver engaging help and policy content across mobile devices, formats, and platforms.
Tupple - Available on IOS, Tupple is the virtual friend that recommends topics to share and lets you create together on the world's first vertical + horizontal social feed.