In computing, time-sharing is the sharing of a computing resource among many users at the same time by means of multiprogramming and multi-tasking.Its emergence as the prominent model of computing in the 1970s represented a major technological shift in the history of computing. By allowing many users to interact concurrently with a single computer, time-sharing dramatically lowered the cost of providing computing capability, made it possible for individuals and organizations to use a computer without owning one, and promoted the interactive use of computers and the development of new interactive applications. History Batch processing The earliest computers were extremely expensive devices, and very slow in comparison to later models. Machines were typically dedicated to a particular set of tasks and operated by control panels, the operator manually entering small programs via switches in order to load and run a series of programs. These programs might take hours to run. As computers grew in speed...

The United States Department of the Interior (DOI) is one of the executive departments of the U.S. federal government headquartered at the Main Interior Building, located at 1849 C Street NW in Washington, D.C. It is responsible for the management and conservation of most federal lands and natural resources, and the administration of programs relating to Native Americans, Alaska Natives, Native Hawaiians, territorial affairs, and insular areas of the United States, as well as programs related to historic preservation. About 75% of federal public land is managed by the department, with most of the remainder managed by the Department of Agriculture's Forest Service. The department was created on March 3, 1849. The department is headed by the secretary of the interior, who reports directly to the president of the United States and is a member of the president's Cabinet. The current secretary is Deb Haaland. As of mid-2004, the department managed 507 million acres (2,050,000 km2) of surface land, or about one-fifth of the land in the United States. It manages 476 dams and 348 reservoirs through the Bureau of Reclamation...

PLATO (Programmed Logic for Automatic Teaching Operations), also known as Project Plato and Project PLATO, was the first generalized computer-assisted instruction system. Starting in 1960, it ran on the University of Illinois' ILLIAC I computer. By the late 1970s, it supported several thousand graphics terminals distributed worldwide, running on nearly a dozen different networked mainframe computers. Many modern concepts in multi-user computing were first developed on PLATO, including forums, message boards, online testing, email, chat rooms, picture languages, instant messaging, remote screen sharing, and multiplayer video games. PLATO was designed and built by the University of Illinois and functioned for four decades, offering coursework (elementary through university) to UIUC students, local schools, prison inmates, and other universities. Courses were taught in a range of subjects, including Latin, chemistry, education, music, Esperanto, and primary mathematics. The system included a number of features useful for pedagogy, including text overlaying graphics, contextual assessment of free-text answers, depending on the inclusion of keywords...

The quagga ( or ) (Equus quagga quagga) is a subspecies of the plains zebra that was endemic to South Africa until it was hunted to extinction in the late 19th century. It was long thought to be a distinct species, but early genetic studies have supported it being a subspecies of plains zebra. A more recent study suggested that it was the southernmost cline or ecotype of the species. The quagga is believed to have been around 257 cm (8 ft 5 in) long and 125–135 cm (4 ft 1 in – 4 ft 5 in) tall at the shoulder. It was distinguished from other zebras by its limited pattern of primarily brown and white stripes, mainly on the front part of the body. The rear was brown and without stripes, and appeared more horse-like. The distribution of stripes varied considerably between individuals. Little is known about the quagga's behaviour, but it may have gathered into herds of 30–50. Quaggas were said to be wild and lively, yet were also considered more docile than the related Burchell's zebra. They were once found in great numbers...

Children's Day is a commemorative date celebrated annually in honor of children, whose date of observance varies by country. In 1925, International Children's Day was first proclaimed in Geneva during the World Conference on Child Welfare. Since 1950, it is celebrated on June 1 in many countries. World Children's Day is celebrated on 20 November to commemorate the Declaration of the Rights of the Child by the UN General Assembly on 20 November 1959. In some countries, it is Children's Week and not Children's Day. The Sikhs celebrate Children Day on 20 December to 27 December. In the U.S., Children's Day is celebrated on the second Sunday of June. History Origins Children's Day began on the second Sunday of June in 1857 by Reverend Dr. Charles Leonard, pastor of the Universalist Church of the Redeemer in Chelsea, Massachusetts: Leonard held a special service dedicated to, and for the children. Leonard named the day Rose Day, though it was later named Flower Sunday, and then named Children's Day. Children's Day was first officially declared...