ShareX - ShareX is a free and open source program that lets you capture or record any area of your screen...
X Steps Recorder - A clone of Microsoft's Problem Steps Recorder, but for linux.
LICEcap - A straightforward, high performance application that enables users to capture a portion of the desktop and save it to . GIF or . LCF, LICEcap is available for download as a GPL free software.
Folge - The fastest tool for creating step-by-step guides.
Snagit - Screen Capture Software for Windows and Mac
Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.