MediaWiki - MediaWiki is a free software wiki package written in PHP, originally for use on Wikipedia.
Dozuki - Dozuki is a web-based tool for creating and distributing step-by-step documentation.
TiddlyWiki - a non-linear personal web notebook
ClassVR - VR Training Simulator
Confluence - Confluence is content collaboration software that changes how modern teams work
ScreenSteps - IT Training Docs For Your Cloud Implementation. Use ScreenSteps when your company implements new cloud technology and you need training docs