Thum.io - A real-time website screenshot generator

Greenshot - Greenshot is a free and open source screenshot tool that allows annotation and highlighting using the built-in image editor.

Scrola - Create scrolling website screenshots, easily

MWSnap - MWSnap is basically a free to use Windows snapping tools that are used for snapping any part of the screen that is currently displaying on the front of all opened programs and windows.

Microlink screenshot - Take a screenshot of any website

Shutter - Shutter is a feature-rich screenshot program.