Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.
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.
ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
Magnifixer - Magnifixer is a screen magnifier utility.
LightShot - The fastest way to take a customizable screenshot.
ZoomIt - Presentation utility for zooming and drawing on the screen.