Haloarchaea have developed into model organisms that are utilized to study many biological processes. Examples are the mechanisms of chromosome maintenance, gene expression and its regulation, protein export and degradation, and motility and sensing. In addition to the analysis of model species like Halobacterium salinarum and Haloferax volcanii, natural communities have been characterized. Halophilic Archaea were found in low-salt environments and are thus more widespread than previously thought.