Saarai was a combination of Jedi and Sith teachings developed by Nikkos Tyris. It combined Tyris's own Jedi training with the techniques he learned from the holocron of Volfe Karkko. Tyris eventually left the Jedi Order and became one of Count Dooku's Dark Acolytes during the Clone Wars.
In the Sith, "saarai" meant "truth." The followers of these teachings were called Jensaarai, or "hidden followers of truth." Their leader was called the Saarai-kaar, or "keeper of truth."