Sydney Synthetic Intellect Institute

The Sydney Synthetic Intellect Institute, or "Double S.I.," was a facility located in Sydney, Australia on planet Earth. "SSII" worked with the creation of AI constructs for the UNSC, theorizing new approaches and calculating the details necessary for the creation of the AI. The experts at this institute created Jerrod, the first functional "micro" AI.

Dr. Catherine Halsey was familiar with this institute. It is not clear if she attended it or not, but the researchers there let her borrow Jerrod to use in the field before the Battle of Reach.