Satan (Hebrew: שָּׂטָן satan, meaning "adversary"; Arabic: شيطان shaitan, meaning; "astray", "distant", or sometimes "devil") is a figure appearing in the texts of the Abrahamic religions who brings evil and temptation, and is known as the deceiver who leads humanity astray. Some religious groups teach that he originated as an angel who fell out of favor with God, seducing humanity into the ways of sin, and who has power in the fallen world. In the Hebrew Bible and the New Testament, Satan is primarily an accuser and adversary, a decidedly malevolent entity, also called the devil, who possesses demonic qualities.

Security Administrator Tool for Analyzing Networks (SATAN) was a free software vulnerability scanner for analyzing networked computers. SATAN captured the attention of a broad technical audience, appearing in PC Magazine and drawing threats from the United States Department of Justice. It featured a web interface, complete with forms to enter targets, tables to display results, and context-sensitive tutorials that appeared when a vulnerability had been found.