- "It's the ISOs, man! Isomorphic Algorithms."
- ―Kevin Flynn[src]
|Derezzed Date||1989 (mostly)|
|Circuitry Color||Various; namely, White and Green|
|Description||Normal program appearance|
|Out of universe information|
Isomorphic Algorithms (better known as ISOs) are a race of programs that spontaneously evolved on the Grid, as opposed to being created by users. Their existence is considered a miracle by Kevin Flynn; however, Clu 2 considers them to be an obstruction in his mission to create the perfect system.
ISOs differ from standard programs with distinctions in their appearance and capabilities, but where they are truly unique is in their code base. While regular programs conform to the rigid structure defined by their users, ISOs have evolved, complete with a genetic code of sorts that even Kevin Flynn can scarcely comprehend. This inner structure of their code has allowed ISOs to develop beyond the capabilities of regular programs.
Kevin Flynn and Clu 2 discovered the first ISO in 1984 while at the edge Tron City. Subsequent to his betrayal, Clu initiated a genocidal assault on the ISOs which was later referred to as the Purge. By the time of TRON: Legacy, Quorra is the last known ISO alive, after Kevin Flynn saved her from the Purge.
There are thought to be no ISOs remaining in the system after Quorra left the Grid.
ISOs have a glowing symbol on their arm and some depictions also show other markings on their skin. Their color circuitry is usually white, but the Bostrumites, such as Gibson, modified their circuitry to glow bright green.
The symbol in their arm represents their gender. The female ISO symbol is a hexagon, followed by a "T" shape, while the male ISO symbol replaces the cross with a sideways "V" shape. In TRON: Evolution - Battle Grids the male/female choice is distinguished by each of these symbols.