X Steps Recorder - A clone of Microsoft's Problem Steps Recorder, but for linux.
Dr.Explain - Dr.Explain software is a help file authoring tool.
Folge - The fastest tool for creating step-by-step guides.
WinCHM - Creating CHM file, Make CHM file, Web Help. WinCHM Pro - Help authoring software (CHM, WebHelp, DOC, PDF) . With this powerful tool you can not only create chm file from scratch, but also convert a set of existing HTML files to a chm file.
Snagit - Screen Capture Software for Windows and Mac
Document360 - Self-service knowledge base software focused on SaaS Products & Enterprise Software Projects.