There are a variety of free alternatives to Windows Vista's Snipping Tool. Jing, which allows users to share their screenshots easily, and Skitch, which allows users to annotate and draw on their screenshots, are both freeware that Lifehacker recommends as similar to Snipping Tool.
Greenshot and Lightshot are two other free alternatives to the Windows Snipping Tool. Snipping Tool is included with all versions of Microsoft Windows since Windows Vista, including Windows 7 and Windows 8. It allows users to capture images of all or a part of their PC screen, as well as annotating and sharing their screen captures.