What's the name of the evil computer program in "TRON"?

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"Tron" hit theaters in 1982 with groundbreaking computer graphics and a premise about getting digitized and zapped into a computer world. Inside this digital landscape, programs looked like people in glowing outfits, and they all lived in fear of one particular entity that had grown way beyond its original programming. This digital tyrant had seized control of the entire computer world and was plotting to break into the real world next. What was the name of this villainous program that ruled over the digital realm?



