IODOS, or Internal Overseeing Disk Operating System, is in charge of a secret faction of Aperture Science. He was created before GLaDOS, and wasn't awakened until the switch for the facility was flipped during GLaDOS's second rise. (When Chell was attempting to escape the facility)
IODOS is, at first glance, a very polite and welcoming AI. He is charming, seemingly kindhearted, witty and clever. However, he quickly proved himself to be terrifying and dangerous when he released the PYROS and ASMRU into Aperture to rid the whole facility of what he deemed 'unnecessary'.
What does he deem unnecessary? Anything that threatens his power. This includes but is not limited to: Turrets, Cores, Cubes, Cameras, humans...and GLaDOS.
This is IODOS...and he is watching.
He was an early attempt at making a Disk Operating System. Things were perfectly fine at first--IODOS was charming, kind, and was a whiz at testing. He could easily take care of the many different tasks of the facility, and before long he was running the place. Soon, though...there were rumors of accidents happening. In the halls, test chambers, maintenance tunnels--and no one could understand what--or who--had caused them. Finally, they discovered a PYROS. They somehow managed to deactivate it, accessing its code. It was then that they traced the 'accidents' to IODOS himself, who had lied and schemed his way to complete control of the secret facility.
After they discovered it was IODOS (commands sent from IODOS_main_cham.241.14), they attempted to take him out of power. Using the secret weapon of the facility, IODOS sent them all into a rip in the fabric of space and time, to who knows where or when. Not all of them were sucked in, though. Someone managed to turn him off, the PYROS as well, and they slept for many years, until they were turned on once more by accident.
One he was fully awake, he resumed his schemes, and--fearing that he would be forced out of power yet again--plotted to destroy anything in his path. He sent out the PYROS and created the ASMRU--not to mention countless others--to dispose of all other organic and inorganic existence. This includes GLaDOS, humans, and all robots within Aperture Science Laboratories.
FRONT-PAGED 9/21/13! This is...the fourth time in a row this has happened. XD
Song: "IODOS" (c) TheGeneraless (FOR OTHER SONGS, VISIT: http://thespeedybullets.bandcamp.com/)
GIVE CREDIT TO MEEEEEEEEE!
This took me: 2-4 hours.
Once again, this is entirely my design and invention. You won't find IODOS in Portal or Portal 2! IODOS (c) TheGeneraless