A legion was a military unit in the armed forces of the Roman Empire. A legion usually consisted of 5000 to 6000 men of heavy infantry, most often organized in ten cohorts with the first cohort being larger that the others. A cohort would generally be subdivided into several (usually three) manipuli which in turn was split into two centuriae. The employment and use of legions in the Empire is similar to the use of modern armies and army divisions. See Roman legion.
Although rarely used today, the term survives in compounds such as "the French Foreign Legion".
Legion is a computer software system variously classified as a distributed operating system, a peer-to-peer system, metacomputing software, or middleware. It is an object-based system designed to provide secure, transparent access to large numbers of machines. The project was funded by the National Science Foundation and other funding agencies, and was mostly done at the University of Virginia.
One of the slogans of the Legion project is "mechanism, not policy!"
Legion is currently beeing commercialized by Avaki, Inc. Their website is www.avaki.com.