SQL Map

Discuss sqlmap, an automated tool for sql injection and database takeover in 600 words or more. How does it work? Where do you get it? How much does it cost? Who developed it? For what purpose?  Why do we need an automated tool for sql injection?  Are there other 'tools' like this available?

Cite your sources. Do not copy. Write in essay format not in bulleted, numbered or other list format.