Advanced Research Projects Agency

The Advanced Research Projects Agency (ARPA) was the original name for the Defense Advanced Research Projects Agency (DARPA), the central research and development organization for the Department of Defense.

What is now the Defense Advanced Research Projects Agency was originally named ARPA, then in March 1972 added a "D" (for defense) to become DARPA, was renamed ARPA again in February 1993, and then renamed DARPA during March 1996.

The Department of Homeland Security (DHS) has its own version of ARPA, the Homeland Security Advanced Research Projects Agency (HSARPA), created by the Homeland Security Act of 2002. Whereas DARPA's technological research focuses externally, towards threats outside America's borders, HSARPA directs its research towards perceived threats from within the country.

For more on HSARPA see Homeland Security Research Projects Agency

For more on DARPA see Defense Advanced Research Projects Agency