DARPA - US  Defense Advanced Research Projects Agency
The Defense Advanced Research Projects Agency (DARPA) is the central research and development organization for the Department of Defense (DoD). It manages and directs selected basic and applied research and development projects for DoD, and pursues research and technology where risk and payoff are both very high and where success may provide dramatic advances for traditional military roles and missions.

AFOSR - US Air Force Office of Scientific Research
AFOSR continues to expand the horizon of scientific knowledge through its leadership and management of the Air Force's basic research program. As a vital component of the Air Force Research Laboratory (AFRL), AFOSR's mission is to support Air Force goals of control and maximum utilization of air, space, and cyberspace. AFOSR accomplishes its mission by investing in basic research efforts for the Air Force in relevant scientific areas. Central to AFOSR's strategy is the transfer of the fruits of basic research to industry, the supplier of Air Force acquisitions; to the academic community which can lead the way to still more accomplishment; and to the other directorates of AFRL that carry the responsibility for applied and development research leading to acquisition.

DOD - US Department of Defense
The United States Department of Defense is the federal department charged with coordinating and supervising all agencies and functions of the government relating directly to national security and the military.

DOE - US Department of Energy
The Department of Energy is the single largest Federal government supporter of basic research in the physical sciences in the United States, providing more than 40 percent of total Federal funding for this vital area of national importance. It oversees, and is the principal Federal funding agency of, the Nation's research programs in high-energy physics, nuclear physics, and fusion energy sciences.  Such a diverse research portfolio supports tens of thousands of principal investigators, post-doctoral students, and graduate students who are tackling some of the most challenging scientific questions of our era.

DTRA - US Defense Threat Reduction Agency  

The Defense Threat Reduction Agency is a combat support agency of the U.S. Department of Defense.  DTRA's  vision is to make the world safer by reducing the threat of weapons of mass destruction. The Defense Threat Reduction Agency safeguards America and its allies from Weapons of Mass Destruction (chemical, biological, radiological, nuclear, and high explosives) by providing capabilities to reduce, eliminate, and counter the threat, and mitigate its effects. Under DTRA, Department of Defense resources, expertise and capabilities are combined to ensure the United States remains ready and able to address the present and future WMD threat.