The Iris was a Nintendo handheld that never left prototype stages before evolving into the Nintendo DS/Nitro in early 2004. As such, early DS prototypes were referred to as Iris, and the SDK was also the "Iris SDK". These prototypes had one screen, no touchscreen, and no wireless modules. (Source: user "subbie" on AssemblerGames).
The Iris SDK was leaked in 2020 as part of the Zammis Clark Breach.