Just A Rather Very Intelligent System (J.A.R.V.I.S.) is Iron Man's artificially intelligent computer. He runs Stark's Home and Avengers Tower and also communicates with him in his Iron Man Armor.
Biography
Iron Man
JARVIS was introduced as an AI system that controls Tony Stark's house. He also helped Tony create the Iron Man suit sometimes added pointers or suggestions. He could talk to Tony through the suit and informed him of the icing problem and gave him stats.
Iron Man 2
To Be Added
The Avengers
To Be Added