DOD: Defense Information Systems Agency
"The Defense Information Systems Agency is a combat support agency responsible for planning, engineering, acquiring, fielding, and supporting Global Net-Centric Solutions and operating the Defense Information System Network to serve the needs of the President, Vice President, the Secretary of Defense, and the other DoD Components, under all conditions of peace and war. "

The website contains press accounts of the agency's impact on DOD-wide IT systems, including:

"The Defense Information Systems Agency has hired DLT Solutions Inc., of Herndon, Va., to provide Red Hat Linux open-source software to the Defense Department in support of its Enterprise Software Initiative."