Dozuki - Dozuki is a web-based tool for creating and distributing step-by-step documentation.
Documize - Enterprise-grade wiki and knowledge management platform
ClassVR - VR Training Simulator
ReadTheDocs - Spend your time on writing high quality documentation, not on the tools to make your documentation work.
ScreenSteps - IT Training Docs For Your Cloud Implementation. Use ScreenSteps when your company implements new cloud technology and you need training docs
HackMD - Fast and flexible, real-time collaborative markdown, inspired by Hackpad.