ARVID stood for ARtificial Viral Intelligence Destabilisation.
It was a short-lived experiment with the production of Artificial Intelligence by means of destroying a stable network in complicatedly specific ways, in much the same way that human brain cells were destroyed over time. The experiment was "short lived" in any number of senses, not least because the AIs it produced, as a result of their continually degenerative state, were at best hideously erratic and at worst outright homicidal maniacs. It was employed by Volan Sleed to be the Master of Ceremonies for his maze. (PROSE: The Infernal Nexus)
ARVID was also the ship's computer for the Titanian Queen. (PROSE: Ship of Fools)