GLaDOS

GLaDOS (Genetic Lifeform and Disk Operating System) is an artificial intelligence created by Aperture Science. She is the antagonist throughout Portal and the first half of Portal 2's single-player campaign. As the overseer and highest of authorities of the Enrichment Center, GLaDOS resides in the Central AI Chamber.

GLaDOS briefly becomes an ally to Chell during the second half of the single-player campaign of Portal 2 after Wheatley takes over the facility. In the cooperative campaign, she is the testing supervisor for ATLAS and P-body.

Appearance
She is a large artificial operation intelligence aperture robotic.

Fun Facts

 * She also recreates the Drones from abandoned Sally's Mothership.

Trivia

 * Some of Caroline's deleted lines indicate she in fact did not want to become GLaDOS. She says, and repeats several times, that she "does not want this," once even speaking to Cave directly: "No, listen to me. Sir, I don't want this." This could explain GLaDOS's resentment toward the scientists and her frequent attempts to kill them since they were the ones to put Caroline in the prototype model of GlaDOS.
 * However, it is possible that GLaDOS's murderous tendencies could be attributed more to the central mainframe rather than her own programming, given her and Wheatley's behavior while in control of the facility and during the course of the game.
 * GLaDOS's Intelligence Core in Portal was actually reciting the cake recipe, which can also be found on the many active monitors around the offices of the Enrichment Center, even in Portal 2.
 * GLaDOS is strongly reminiscent of HAL 9000, the murderous A.I. computer of 2001: A Space Odyssey; even the single, red "eye" of the security cameras and Sentry Turrets are reminiscent of HAL. However, those who read the book, 2001: A Space Odyssey, will find that HAL 9000 was driven to his actions in an attempt to rationalize two conflicting orders: to conceal the true mission objective and to never hide anything from the crew. He reached the conclusion that if the crew were dead, he would no longer have to hide the information since there would be nobody to hide it from. Because GLaDOS became self-aware and developed a sinister personality, it is safe to assume she is more alive, and more antagonistic than HAL 9000.