Nowadays, studies are increasingly emerging on the extremophiles inhabiting the extreme environments on earth. Covering 3/4 of the Earth's surface area, the ocean nurtures a variety of extremophiles found in extreme marine environments such as hydrothermal vents, hot springs, saline lakes and deep sea. These extremophiles can adapt to extreme high temperature, extreme low temperature, high pressure, high salinity, high radioactivity and extreme acidity and alkalinity. Their special biodiversity, together with their genetic background and unique metabolic pathways have evoked vast interests of scientist and industries. Research on extremophiles from variety of submarine geological landforms will be helpful to gain the knowledge on the origin of life, biodiversity, discovery and utilization of new natural resources, and geobiology. On the other hand, application orientated studies on panel of enzymes and variety of other unique active substances with extremophiles, have already been attempted with their potency well revealed. This review covers the latest progress on the studies covering the diversity of extremophiles, the development and utilization of new resources, research methods and techniques, respectively.