X Steps Recorder - A clone of Microsoft's Problem Steps Recorder, but for linux.
Virtual Magnifying Glass - Virtual Magnifying Glass, a free, open source, screen magnification program for Windows, Linux, FreeBSD and Mac OS X. Free full version download and instructions for use.
Folge - The fastest tool for creating step-by-step guides.
Magnifixer - Magnifixer is a screen magnifier utility.
Snagit - Screen Capture Software for Windows and Mac
ZoomIt - Presentation utility for zooming and drawing on the screen.