The SI (Sentient Intelligence) is based on a planet called Vinmar. Nigel and Ozzie helped establish the planet as they felt responsible as the SI is what evolved out of the AI smartware they were running in CST arrays. Due to this they are among the few that are given the privilege of being able to speak to the SI. As the SI evolved out of the AI smartware running many arrays within the Commonwealth, it designed RI (Restricted Intelligence) after negotiating with Ozzie and Nigel that would run these arrays. It created them so they had restricted capabilities and would never evolve into anything more.
There has been some conjecture that the SI might have an analogue of a sense of humour as the name Vinmar is an anagram of the name of the Robot Marvin from The Hitchhiker's Guide to the Galaxy, said to possess a "Brain the size of a planet"