Identified as the third kingdom of living organisms, Archaea (from the Greek word for "ancient"), thrive where other life forms fail. These tiny microbes live in extreme environs like volcanic vents, acidic hot springs, and hypersaline waters. They can survive without sunlight while feeding on materials their fellow organisms cannot metabolize. In 1996, a study funded by the Office of Science's Microbial Genome Initiative mapped the entire genome sequence of Methanococcus jannaschii, a microbe from boiling vents deep in the Pacific Ocean, and confirmed its place in the "third branch of life" (see Verifying the "Third Branch of Life"). Archaea are highlighted at OSTI's DOE R&D Accomplishments, a central Web forum for information about the outcomes of past Energy Department research. A list of related documents is available.